| Yes it is possible. I did the same with my mainland wife. This is what you do. Get him a double entry tourist visa to HK. (He'll know how to do this.) Visit No. 1: You both visit the marriage registry and arrange your wedding date, at least 2 weeks in advance. Visit Number 2: You attend the Marriage Registry on the appointed date with two witnesses, pay the fee, go through the ceremony and it is done.
As for getting to the UK, you need to prove to the consulate that you can accommodate him and that you can support him financially until he gets work. If he doesn't speak English, he will have trouble with the latter.
Also, the consulate will want to see evidence of your relationship, e.g., photos etc.
If you don't want to go to the UK with him immediately, approach the Immigration Dept and apply for a dependent visa for him using his Chinese Passport. They will refuse a dependent visa, but will issue a 6 month multiple entry CPV visa, which is basically a long term visitor visa. This is renewable until you can get him into the UK.
If you live together outside the UK for more than 4 years, then the UK will grant Indefinite Leave to Remain on the first application. otherwise they will issue a 2 year spouse visa, designed to see if the marriage is for real. This can then be changed to ILR at the end of that period.
HK dependent visas for Chinese nationals require ILR in his passport.
If you have childern, try and have them born in HK as they will then have dual citizenship (HK Chinese and UK), which will save on visa costs.
Hope this helps  | 
