diff --git a/cinder/volume/drivers/dell_emc/vnx/common.py b/cinder/volume/drivers/dell_emc/vnx/common.py
index ef27f509263..d5babb17a97 100644
--- a/cinder/volume/drivers/dell_emc/vnx/common.py
+++ b/cinder/volume/drivers/dell_emc/vnx/common.py
@@ -102,9 +102,8 @@ VNX_OPTS = [
                 'to maximum number of pool LUNs is reached. '
                 'By default, the value is False.'),
     cfg.BoolOpt('force_delete_lun_in_storagegroup',
-                default=False,
-                help='Delete a LUN even if it is in Storage Groups. '
-                'By default, the value is False.'),
+                default=True,
+                help='Delete a LUN even if it is in Storage Groups.'),
     cfg.BoolOpt('ignore_pool_full_threshold',
                 default=False,
                 help='Force LUN creation even if '
diff --git a/doc/source/configuration/block-storage/drivers/dell-emc-vnx-driver.rst b/doc/source/configuration/block-storage/drivers/dell-emc-vnx-driver.rst
index 42a8dbd4d05..8e58ff697e8 100644
--- a/doc/source/configuration/block-storage/drivers/dell-emc-vnx-driver.rst
+++ b/doc/source/configuration/block-storage/drivers/dell-emc-vnx-driver.rst
@@ -318,7 +318,7 @@ section, the driver will move the volumes out of the storage groups and then
 delete them if the user tries to delete the volumes that remain in the storage
 group on the VNX array.
 
-The default value of ``force_delete_lun_in_storagegroup`` is ``False``.
+The default value of ``force_delete_lun_in_storagegroup`` is ``True``.
 
 Over subscription in thin provisioning
 --------------------------------------
diff --git a/releasenotes/notes/enable-force-delete-lun-d0e05b5d669e40f7.yaml b/releasenotes/notes/enable-force-delete-lun-d0e05b5d669e40f7.yaml
new file mode 100644
index 00000000000..b011dcd0a9c
--- /dev/null
+++ b/releasenotes/notes/enable-force-delete-lun-d0e05b5d669e40f7.yaml
@@ -0,0 +1,15 @@
+---
+upgrade:
+  - |
+    DellEMC Unity: The fix of bug
+    `1825469 <https://bugs.launchpad.net/cinder/+bug/1825469>`_ changes the
+    default value of the ``force_delete_lun_in_storagegroup`` option from
+    ``False`` to ``True``, which means luns will always be force deleted after
+    upgrade.
+fixes:
+  - |
+    DellEMC Unity: Fix bug
+    `1825469 <https://bugs.launchpad.net/cinder/+bug/1825469>`_. The fix
+    enables the ``force_delete_lun_in_storagegroup`` option to ``True`` by
+    default, which makes sure that luns can deleted even when they are still in
+    storage groups.