With the continuous development of the automobile industry, it has put forward higher requirements for the engine performance. In actual production, the failure of vehicle parts often occurs due to various factors. Especially for some parts with complex structure, they are more likely to fail. Therefore, in order to ensure the safe and reliable driving of vehicles and meet the use needs of vehicle owners and improve vehicle quality, this paper uses the finite difference method to model and analyze the design. Then, based on the finite difference method, this paper designed the automobile engine performance model, and tested the function of the model. The test results showed that the automobile engine performance modeling based on the finite difference method used a special process to coat silicon carbide powder on the inner wall of the cylinder block, which can improve its wear resistance and prolong its service life by 1~2 times. The high-grade refractory materials made of it are heat-resistant, small in size, light in weight and high in strength, Good energy-saving effect.