Suspend cards in a folder cannot meet my demand. Because my cards are all distributed in daily documents. I prefer to use tags rather than folders
Agreed
I see the value in that as I use the Daily & Tags more than Docs & Folders
Along the ability to Suspend Documents and Folders, you can suspend Cards by Tagging them with the Suspend Cards PowerUp, or by typing /Suspend.
Would this satisfy your Feature Request? 
If you had cards that had a certain tag would there be a way to apply this suspend cards tag to all of them vs one by one?
IE
Cards are tagged with topic A tag
I want to suspend all cards using this tag
Can I add the suspend cards tag to the topic A tag in 1 (or a couple) clicks vs having to add it to each card manually?