A mixed model using stairs and elevators together to evacuation the persons was built. The computer simulation on the optimum of the occupant evacuation time is realized with the data of Chongqing hotel. When 23 percent of people using elevators, the optimum evacuation time are respectively 938.7 s and 917.4 s. The analysis of the simulation may be used as valuable scientific references for the performance based on fire protection of buildings and the prescription of the emergency plan.