In order to meet the demand for upgrading the fan performance of vehicle cooling system after hybridization, a scheme to increase the downward displacement of fan blades and optimize the fan blade airfoil shape was put forward to limit the eddy current loss at the blade tip clearance. By using CFD and CAE software, the microscopic flow field of cooling fan was analyzed, the fan blade structure was optimized, and the optimization effect was predicted. Experimental verification shows that the optimization scheme can effectively reduce the blade top gap, inhibit the eddy current loss generated by the blade top gap, and hence improve the effective airflow of cooling fan. Combined with the wind resistance curve of whole vehicle, the optimization scheme can increase the actual airflow of whole vehicle by 3.3%, which verifies the validity of optimization scheme.