Considering the different levels of large-scale urgent disaster, Sigmoid time satisfaction function is proposed to evaluate the rescue effect. It builds the shortest rescue path and maximum satisfaction of average time vehicle scheduling model. Chaotic Whale Swarm Algorithm is designed based on Chaos sequence search operator. the improved algorithm is applied to optimize three groups of experimental cases of different sizes, and the results are compared with those of the simulated annealing algorithm and original Whale Swarm Algorithm. Results show that there is little difference in performance when the handling smaller scale of vehicle scheduling, while the improved algorithm gain more advantage over the simulated annealing algorithm and original algorithm as the handling scale getting larger. Chaotic Whale Swarm Algorithm is effective method to deal with emergency vehicle scheduling problem.