PyCharm 2018.1.4
Windows 10
Issue: search box cannot display Chinese character.
but if I go to setting--> material theme--> panels--> check/uncheck Compact Table Cells --> Apply
the search box will become normal and can display Chinese correctly.

ctrl+shift+f --> find in path dialog --> also have the same issue.
You need to change the font in the color scheme settings (Editor > Color Scheme > Color Scheme Font)
color scheme font only change the font of the code, but not the search box.
the font of the code can display the Chinese normally

Ah ok my bad I thought you were talking about the search box in the “find file” dialogs.
You can try to disable the “material fonts” in the features tab and restart the ide.
I have already tried to disable but it's not fixed.
but turn on / off will make the UI have a refresh which cause the issue temporary fixed.
Most helpful comment
I have already tried to disable but it's not fixed.
but turn on / off will make the UI have a refresh which cause the issue temporary fixed.