请问 CH558L/CH559L 是否可以从用户程序跳转到Bootloader？

The following will do the trick.

#define CALL(addr) (((void(*) (void) (unsigned char*) addr)())

Then somewhere in your program use CALL (0xF400);

Note its Not the same as activate by HW contition but download

will work. Changing Config Options on the other hand will be 

ignored.