The dynamic model and joint simulation platform of turbocharged diesel engine was established by using GT-Power and Simulink software. The dynamometer loading mode of natural characteristics and constant speed combination was proposed to simulate and analyze the transient process of diesel engine in plateau environment. Through different loading conditions, the influencing factors of poor transient response of diesel engine during acceleration were analyzed. It was found that engine speed and fuel injection quantity were two important parameters affecting the response of turbocharger. By rapidly increasing the engine speed, increasing the air intake, and then loading at constant speed, the supercharger hysteresis could be overcome, and the high load state of engine hence can be quickly achieved. Accordingly, the simulation method could provide a reference for changing the engine operating conditions by torque intervention and improving the starting response of vehicle during the plateau starting process.