If you have residence permit in China, you can apply for Hong Kong visa from China, there is Immigration Division of the Beijing Office of the Government of the HKSAR which can accept Hong Kong visa application from aliens,
Address: 71, Di'anmen Xidajie, Xicheng District, Beijing 100009)
Telephone Enquiries (852) 2824 6111

You can contact the Beijing Office whether you can submit Hong Kong application to it.