The basic parameters of internal combustion engines reflect the working performance and quality of the internal combustion engine. Therefore it is of great significance to design the operating parameters of vehicle engine by design optimization method. In this paper, hybrid genetic algorithm is adopted to optimize operating parameters of vehicle engine, so that optimization process was simplified and the global optimal solution is ensured reliably. Being satisfied with the heating loading, mechanical loading and the conditions of gas mixture of engine and boundary constraints, the optimization mathematical model is created which is to minimize the heating surface area of engine. Considering the problem of low efficiency and local optimum caused by traditional optimal methods, the hybrid Genetic Algorithm are adopted to solve the optimization model. So that the optimization process is simplified and global optimum is acquired reliably.