The literal translation of the title of this movie is: Heroine Black Rose.
This movie is loosely based on the true story of World War II era Chinese undercover female agent Black Rose who use the profession of singer as her cover. The reason why it was termed "loosely" based on the true story that really happened was because there was political propaganda added, which resulted in some alterations of what really happened:
The protagonist was originally a nationalist agent but before she could really start to organize resistance work, her superior and her comrades fled or captured. Since she was new and just got there after others met their tragic fate, nobody knew her, so she did not blow her cover. She turned to communists for help and organized the resistance network.
This very beginning part of history was altered in the movie and she was described as an agent in or at sympathetic to the communist camp from the very beginning. This alteration is what tarnishes the whole thing.