Along with social economy development, it is attached great significance to have a decision making system for emergency evacuation strategy. The paper mainly discusses about using Genetic Algorithm (GA) to search optimal evacuation strategy. The mathematical model is built based on scrupulous analysis of the traffic data and routing problem. By means of comparing experimental results of genetic algorithm, simulated annealing algorithm and particle swarm algorithm, it can be seen that genetic algorithm has the best performance and can figure out a better evacuation strategy in complex environment than the other two algorithms.