What brands of plug-in capacitors are there in China?

The plug-in capacitors you mentioned include ceramic capacitors, electrolytic capacitors and thin film capacitors.

Manufacturers of ceramic capacitors (including Taiwan Province Province): Huiqiao Electronics (acquired by Huaxin Group), Hou Jun Electronics, Micro Capacitor Electronics, Wansheng Electronics, etc.

Manufacturers of thin film capacitors (including Taiwan Province Province): HJC (Huarong), Youpu Electronics, etc.

Manufacturers of electrolytic capacitors (including Taiwan Province Province): Rong Tai Electronics, Li Long Electronics, Nantong Jianghai, etc.