金山云-文档中心-Comparison of access policies

	ACL	Bucket policy	User policy
Policy type	Resource-based policy	Resource-based policy	User-based policy
Resource operation	Only basic read/write operations are supported.	Many operations are supported, except service operations such as bucket list query.	Most operations are supported, including service operations such as bucket list query.
Authorize other accounts	Supported	Supported	Not supported. You can create a role and select a trusted account for cross-account authorization.
Authorize IAM users	Not supported	Supported	Supported
Authorize roles	Not supported	Supported	Supported

You only want to keep buckets or objects public or private without complex authorization logic.

You want to grant resource-specific permissions to other accounts for cross-account access.
You want to grant resource-specific permissions to IAM users who do not need to log in to the console.

You want to grant resource-specific permissions to IAM users who need to log in to the console.
You want to assign specific roles to IAM users to grant them temporary permissions.