Right-click the database first, then click Properties, and select the Options tab in the property page. Then you can see that the default value in the recovery model is "complete" and changed to "simple". All right.

Then shrink the database (preferably a single file). At this time, you can see that the log files are greatly reduced, and then change the recovery mode to "complete" again.

This method will never cause file loss, and there is no security problem. Please feel free to use it, hehe!