Scenario
If your business no longer needs one or multiple security groups, you can delete them. After you delete a security group, all security group rules in the group will also be deleted.
Preparations
The security group to be deleted is not associated with any instances. If it is associated with an instance, remove it from the security group first. Otherwise, the security group cannot be deleted. For operation instructions, see Removing Instances from a Security Group.
Instructions
1. Log in to the security group console, and go to the security group management page.
2. On the security group management page, select a region and locate the security group you want to delete.
3. In the row of the security group to be deleted, click More > Delete in the action column.
4. In the pop-up dialog box, click OK.