Abstract: The cooling fan, a critical component of the automotive engine cooling module, holds utmost significance in influencing the engine's cooling efficiency, particularly in high-power diesel engines. Its precise positioning has a direct impact on the flow field structures in the engine compartment, the airflow through the radiator and consequently, the engine's heat dissipation performance. In this study, an optimization method is developed to determine the optimal placement of a cooling fan in a new engine compartment. This method aims to refine the layout and flow field structures by closely examining the radiator flow and flow fluctuations, with the fan's position as the variable. The optimization process begins by generating initial design sample points using experimental design methods, followed by geometric parametric modeling. Next, typical vehicle speeds are selected to simulate flow fields in the engine compartment under actual working conditions. A Kriging surrogate model is then established based on the simulation results. A multi-objective optimization is subsequently carried out, aiming to achieve the desired radiator inlet flow and standard deviation of flow rate. The Pareto optimal solution set is obtained through a genetic algorithm, and the results are analyzed using multi-dimensional parameter variable visualization method, which provides a valuable reference for the layout decision of parts in the cabin. The results demonstrate a significant correlation between the positional change of the cooling fan along the vehicle's travel direction and the radiator flow. This correlation provides theoretical support for the global optimality of the layout scheme of the new model's heat dissipation module.