Excuse me! To run blender ,whether should close antivirus software? If not, sometimes antivirus software will treat blender as virus ,but if yes, system is not safety. I want to know others' opion. Thanks.

Sorry! I want to know others' opinion. Thanks.

If you got Blender from a trusted source [the official site - and didn't use any "download helper/manager" programs] then it should be clean/safe. Your antivirus should have a way to make a "rule"/"exception" for or "white-list" a program which would let you tell your antivirus to ignore Blender. That'd be the option I'd probably use.

Alternatively, you could disconnect from the internet and temporarily disable your AV while working with Blender. As long as you've scanned any files on your computer beforehand, and didn't have any issues, that should be safe enough, if a bit of a hassle.

You say its only happening intermittently; if its happening only when working with a specific .blend file, that you may have picked up from somewhere on the net, then that file might warrant a more careful scanning.

I agree with Warlock I have never had my antivirus flag Blender as untrusted either an individual file has been infected or a file you are opening is infected with something I would do a full scan of your system with your antivirus to see what it finds and consider totally uninstalling Blender and reinstalling from a fresh copy of a Blender that has been downloaded from Blender.org

Thanks guys. Here is 360 antivirus that always got mistaken. And good health.