diff --git a/reference/tiflash/upgrade.md b/reference/tiflash/upgrade.md
index e8dbc4be8c3fe..516a5334753c5 100644
--- a/reference/tiflash/upgrade.md
+++ b/reference/tiflash/upgrade.md
@@ -10,9 +10,13 @@ category: reference
 >
 > To upgrade TiFlash from the Pre-RC version to a later version, contact [PingCAP](mailto:info@pingcap.com) for more information and help.
 
+Currently, you cannot upgrade TiFlash by running the `tiup cluster upgrade` command. Instead, take the following steps to upgrade TiFlash:
+
 Before the upgrade, make sure that the cluster is started. To upgrade TiFlash nodes, take the following steps:
 
-1. Run the upgrade command:
+1. Refer to [Scale in a TiFlash node](/how-to/scale/with-tiup.md#sclale-in-a-tiflash-node), and scale in all the TiFlash nodes.
+
+2. Run the upgrade command:
 
     {{< copyable "shell-regular" >}}
 
@@ -20,7 +24,15 @@ Before the upgrade, make sure that the cluster is started. To upgrade TiFlash no
     tiup cluster upgrade test v4.0.0-rc
     ```
 
-2. View the cluster status:
+3. Run the scale-out command:
+
+    {{< copyable "shell-regular" >}}
+
+    ```shell
+    tiup cluster scale-out test scale-out.yaml
+    ```
+
+4. View the cluster status:
 
     {{< copyable "shell-regular" >}}
 
@@ -28,4 +40,4 @@ Before the upgrade, make sure that the cluster is started. To upgrade TiFlash no
     tiup cluster display test
     ```
 
-3. Access the monitoring platform using your browser, and view the status of the cluster.
+5. Access the monitoring platform using your browser, and view the status of the cluster.