The editor is extremely slow when enter play mode on first time.

Unity Engine
1

Each time I enter the play mode spend a lot of time. I profile the editor but can not find any hint to improve it.
Most of the time spend on Loading.ReadObject and LoadingFileHeaders. It seems load the whole project assets.

Is there any way to speed up it?

3161238--240494--EditorSlow_001.png
3161238--240494--EditorSlow_001.png1666×892 153 KB

3161238--240495--EditorSlow_002.png
3161238--240495--EditorSlow_002.png1666×892 153 KB

2

Is there any one know about this issue.
There is no reason why Loading so much object when I enter the play mode. The start scene is almost empty.