Based on three kinds of diesel engine, main characteristics shown in real plateau were analyzed and test cycle applied in plateau simulated test bench was developed in order to solve the insufficient verification of engine performance by using the measured data on road. The results show that diesel engine mainly runs at medium and high speed and load at the altitude of 4 300 m and the parameters such as operating speed, exhaust temperature and coolant temperature are beyond the limit. The coolant temperature is beyond the limit during the operation time of more than 70%. In addition, the diesel engine mainly operated in the area of output power larger than 50% and the supercharging ratio in plateau is slightly larger. The designed cycle is a 600 s test cycle, which represents the operating behavior of diesel engine at high altitude.