Hung Sin Nui learnt the art of Cantonese Opera from her aunt Ho Fu Lin. She was spotted by the famous actor Ma Shi Tsang and became a leading actress at the age of 15.

Hung played alongside Ma in productions like "The Spoiled Brat and Her Groom", "Bitter Phoenix, Sorrowful Oriole", "Wang Zhaojun Marries beyond the Great Wall" and so on. Hung went back to Guangzhou with Ma Shi Tsang in 1955 and joined the Guangdong Cantonese Opera Troupe. Under her leadership, the group gave performances of historical dramas like "Chu Yuan", "Guan Hanqing", and "The Tragedy of Lee Heung Kwan", all with Hung being the leading actress.