How to get a visa to participate HIV conference in Hong Kong?

Dear, considering your situation, you can apply for a HK visit entry permit to go there to participate in the conference. The first thing is to prepare the required documents including copy of your passport, the application form attached with a passport-style photo, proof of your financial support, flight itinerary, hotel reservation and an invitation letter from the conference organizer.
Afterwards, submit the application to the embassy of PRC to apply for it.