The permanent exhibition, which is scheduled to open next Saturday, commemorates those killed in the authorities' brutal crushing of pro-democracy protesters in Beijing on June 3-4, 1989.
All reference to the crackdown is banned on the mainland, where many remain unaware of it.
The museum is funded by the Alliance in Support of Patriotic Democratic Movements of China, which also organises the annual June 4 candlelit vigil in Hong Kong attended by tens of thousands.
"By letting them remember and letting them know what actually happened, they will have anger towards the Communist Party - which in order preserve its power, went to the extent of shooting its own people.
Organisers will use social media, including Weibo - China's equivalent to Twitter - to promote the museum, Lee said.
It also includes a two-metre tall statue of the Goddess of Democracy, similar to one erected at Tiananmen Square during the protests almost 25 years ago.
Beijing has never provided an official final toll for the military crackdown, which was condemned worldwide. Independent observers tallied more than 1,000 dead in Beijing, without including victims elsewhere.
The Chinese Communist Party branded the Tiananmen protests a "counter-revolutionary rebellion" but pro-democracy advocates in Hong Kong have consistently commemorated the incident.
