diff --git a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandbox.java b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandbox.java
index 89f6a7adca..a39859abed 100644
--- a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandbox.java
+++ b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandbox.java
@@ -86,8 +86,8 @@ public void start() throws Exception {
                     log.debug("[sandbox] Branch B: workspace lost, restoring from snapshot");
                     Optional<InputStream> archive = openSnapshotArchive(snapshot);
                     if (archive.isPresent()) {
-                        doSetupWorkspace();
                         try (InputStream stream = archive.get()) {
+                            doSetupWorkspace();
                             doHydrateWorkspace(stream);
                         }
                         workspaceSpecApplier.applyWorkspaceSpec(spec, true);
@@ -104,8 +104,8 @@ public void start() throws Exception {
                 if (archive.isPresent()) {
                     // Branch C: restore from snapshot + all spec entries
                     log.debug("[sandbox] Branch C: restoring from snapshot");
-                    doSetupWorkspace();
                     try (InputStream stream = archive.get()) {
+                        doSetupWorkspace();
                         doHydrateWorkspace(stream);
                     }
                     workspaceSpecApplier.applyWorkspaceSpec(spec, false);
diff --git a/agentscope-harness/src/test/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandboxSnapshotCleanupTest.java b/agentscope-harness/src/test/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandboxSnapshotCleanupTest.java
new file mode 100644
index 0000000000..64795107bd
--- /dev/null
+++ b/agentscope-harness/src/test/java/io/agentscope/harness/agent/sandbox/AbstractBaseSandboxSnapshotCleanupTest.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.harness.agent.sandbox;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.CALLS_REAL_METHODS;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.mockito.Mockito.withSettings;
+
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshot;
+import java.io.IOException;
+import java.io.InputStream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.mockito.InOrder;
+
+class AbstractBaseSandboxSnapshotCleanupTest {
+
+    @ParameterizedTest
+    @ValueSource(booleans = {false, true})
+    void closesSnapshotAfterSuccessfulHydration(boolean previouslyReady) throws Exception {
+        InputStream archive = mock(InputStream.class);
+        AbstractBaseSandbox sandbox = sandboxForRestore(previouslyReady, archive);
+
+        sandbox.start();
+
+        InOrder order = inOrder(sandbox, archive);
+        order.verify(sandbox).doSetupWorkspace();
+        order.verify(sandbox).doHydrateWorkspace(archive);
+        order.verify(archive).close();
+        assertTrue(sandbox.isRunning());
+        assertTrue(sandbox.getState().isWorkspaceRootReady());
+    }
+
+    @ParameterizedTest
+    @ValueSource(booleans = {false, true})
+    void closesOpenedSnapshotWhenWorkspaceSetupFails(boolean previouslyReady) throws Exception {
+        InputStream archive = mock(InputStream.class);
+        AbstractBaseSandbox sandbox = sandboxForRestore(previouslyReady, archive);
+        IOException setupFailure = new IOException("workspace setup failed");
+        doThrow(setupFailure).when(sandbox).doSetupWorkspace();
+
+        SandboxException.WorkspaceStartException failure =
+                assertThrows(SandboxException.WorkspaceStartException.class, sandbox::start);
+
+        assertSame(setupFailure, failure.getCause());
+        assertFalse(sandbox.isRunning());
+        assertFalse(sandbox.getState().isWorkspaceRootReady());
+        verify(sandbox, never()).doHydrateWorkspace(any());
+        verify(archive).close();
+    }
+
+    @ParameterizedTest
+    @ValueSource(booleans = {false, true})
+    void preservesSetupFailureWhenClosingSnapshotAlsoFails(boolean previouslyReady)
+            throws Exception {
+        InputStream archive = mock(InputStream.class);
+        IOException closeFailure = new IOException("archive close failed");
+        doThrow(closeFailure).when(archive).close();
+        AbstractBaseSandbox sandbox = sandboxForRestore(previouslyReady, archive);
+        IOException setupFailure = new IOException("workspace setup failed");
+        doThrow(setupFailure).when(sandbox).doSetupWorkspace();
+
+        SandboxException.WorkspaceStartException failure =
+                assertThrows(SandboxException.WorkspaceStartException.class, sandbox::start);
+
+        assertSame(setupFailure, failure.getCause());
+        verify(archive).close();
+        assertArrayEquals(new Throwable[] {closeFailure}, setupFailure.getSuppressed());
+    }
+
+    private AbstractBaseSandbox sandboxForRestore(boolean previouslyReady, InputStream archive)
+            throws Exception {
+        SandboxSnapshot snapshot = mock(SandboxSnapshot.class);
+        when(snapshot.isRestorable()).thenReturn(true);
+        when(snapshot.restore()).thenReturn(archive);
+        SandboxState state = new SandboxState() {};
+        state.setWorkspaceSpec(new WorkspaceSpec());
+        state.setWorkspaceRootReady(previouslyReady);
+        state.setSnapshot(snapshot);
+        AbstractBaseSandbox sandbox =
+                mock(
+                        AbstractBaseSandbox.class,
+                        withSettings().useConstructor(state).defaultAnswer(CALLS_REAL_METHODS));
+        doReturn(false).when(sandbox).probeWorkspaceRootForPreservedResume();
+        return sandbox;
+    }
+}
diff --git a/docs/v2/en/docs/harness/sandbox.md b/docs/v2/en/docs/harness/sandbox.md
index a5da5e3075..c89ecdd33c 100644
--- a/docs/v2/en/docs/harness/sandbox.md
+++ b/docs/v2/en/docs/harness/sandbox.md
@@ -65,6 +65,8 @@ The sandbox snapshots its workspace at each `call()` end and restores at the nex
 - Container gone → reboot from snapshot, restore workspace
 - No snapshot → full init from `WorkspaceSpec` (cold start)
 
+An opened snapshot archive is closed even if workspace setup fails during restoration.
+
 Where snapshots land is decided by `snapshotSpec`:
 
 | Option | When |
diff --git a/docs/v2/zh/docs/harness/sandbox.md b/docs/v2/zh/docs/harness/sandbox.md
index 6d5ace317d..0fd33a5060 100644
--- a/docs/v2/zh/docs/harness/sandbox.md
+++ b/docs/v2/zh/docs/harness/sandbox.md
@@ -65,6 +65,8 @@ agent.call(msg, RuntimeContext.builder()
 - 容器没了 → 拿快照重新起一个，恢复工作区
 - 没快照 → 按 `WorkspaceSpec` 全量初始化（冷启动）
 
+恢复时已经打开的快照归档流，即使工作区初始化失败也会关闭。
+
 快照存到哪里取决于你配的 `snapshotSpec`：
 
 | 选项 | 适合 |