Why the storage of Documents showing wrong in mac?

The System Information view is misleading by naming it "Documents"

Under the category "Documents" it will trow everything in in that is not in the other sidebar listed categories.

For example in my case, it will show all my Movies as Documents.

The misunderstood display .. it says my "Documents" are 92GB which is not true for Documents Folder.?

In your case....

I was searching for this question. why the summary tell different size with the "actual size calculation" then I realize, maybe there something like some hidden folder in the calculation. with this idea, I came up to try to show the hidden files.

so, I press shortcut "cmd + shift + period" and all the hidden folders is shown. It came up with the Library folder, which has almost half of the calculated size and another folder.

You placed a screenshot of the The Storage Management.app. This particular utility shows a categorized view of your disk contents.

What is Storage Management App

Storage Management.app is a utility app which gives you an overall perspective of what do you have in your system. Whether its loaded with applications or iOS Backups or Books or you haven't simply emptied your trash. It's not misleading, it is the way it is designed.

It categorized several file types as Documents e.g. xip, zip, dmg, mov and even unknown file types etc. Most of these file types are larger in file sizes.

If you want to see how much each folder on disk is taking space, you should use Finder > Get Info to see what you're looking for.