Yes, he needs to apply for a Hong Kong visa in advance through Chinese embassy in Dubai. Hk visa requirements are as follows:
1. Your Passport/travel document valid for more than 6 months;
2. One completed HK visa application form affixed with one passport-sized photo;
3. Hotel reservation and return/onward ticket.
4. your valid employee card or residence permit in UAE.

Dear sir,

i'm planning to travel to U.K via H.k, i'm form pakistan, but living and working in Dubai, U.A.E, I want to know whre i can apply for visa nd how much time it need to get visa granted or no
Thanks, my email id is hotmail.com|knaveed.

You can apply for Hong Kong transit visa from China consulate in Dubai, it takes 4 working days for visa processing.