I've supposed that Chinese glyphs is already included in STIX fonts. If yes and if you are using Windows version then just use LoadFont (see http://mathgl.sourceforge.net/doc_en/Font-settings.html#loadfont) for loading its full version. Note, that only limited set of STIX glyphs are build-in into MathGL windows binaries by default.
could mathgl2 support Chinese font by default?
I've supposed that Chinese glyphs is already included in STIX fonts. If yes and if you are using Windows version then just use LoadFont (see http://mathgl.sourceforge.net/doc_en/Font-settings.html#loadfont) for loading its full version. Note, that only limited set of STIX glyphs are build-in into MathGL windows binaries by default.
If not or if you want to use yours own font files then just use https://sourceforge.net/p/mathgl/code/HEAD/tree/font_tools/ to make it.