Abstract: The The working process and thermal load of the cylinder liner of a high power diesel engine is moddled by means of GT-Power and ANSYS. The thermal load model is verified through hardness tests. Simulations are performed with variable timing parameters and the influence of valve timing on the thermal load of the liner is calculated. Taguchi experiment design method and analysis of variance are used to analyze the weights of valve timing parameters in terms of their effects on the thermal load. The optimization of the liner design is also performed. The research finds that exhaust advance angle and intake advance angle have higher weights than others in terms of the influence on thermal load of liner.