The invention discloses a crowd evacuation simulation method and system based on an evacuation path set. The method includes the steps: extracting characteristics of an evacuation scene to obtain a two-dimensional model of the evacuation scene; acquiring all available evacuation paths based on the two-dimensional model of the evacuation scene and a social force model fusing obstacle avoiding strategies to obtain the evacuation path set; performing discretization operation on all paths in the evacuation path set, and calculating crowd distribution degree and block degree information in real time to obtain evaluation values of each individual in crown for the all paths in the evacuation path set; building a roulette according to the evaluation values of each individual in the crown for the all paths in the evacuation path set, and selecting an optimum evacuation path by the aid of pseudo random selection strategies based on the roulette and stable factors to achieve simulation of crowd evacuation processes. According to the method, evacuation strategies are changed in real time by a simulation individual according to current evacuation environments, and safety evacuation plans of sudden events can be scientifically guided.