I'm a govt service holder. My wife doing private job. She got a chance to go China for official purpose

I m a govt service holder. my wife doing private job. she got a chance to go china for official purpose. for this purpose she also have invitation letter from china. Now she wants to take me. by this time i also wants to go to treatment myself . now what should I do? am I need invitation? pls let me know.

Jashim/BD