You can submit your HK visa application to Chinese embassy in UAE. It usually takes more than 2 weeks to process the visa and it has to be approved by the Immigration Department of Hong Kong SAR.
The following documents are required:
1. A completed Visa Application Form for HK.
2. A copy (A-4 size) of the passport and U.A.E. residence visa, both of which should be valid for more than six months and a photograph as in the passport.
3. An employment/no-objection letter from your company, which clarifies your full name, position, nationality, passport number and the purpose of the visit, and a copy of the trade license, if self-employed.
4. An invitation letter from the sponsor in Hong Kong (for business visit).
5. Detailed schedule, confirmed hotel reservation and round air ticket booking (for tourism).
6. Original personal bank statement for the last three months.