Abstract: Addresses the problem of additional oil temperature increase with a fan installed in the oil cooling system and presents a feasible model which complements the method for predicting the performance of the oil cooling system.On the basis of the system model developed,structure parameters were optimized with genetic algorithm to improve the accuracy.With this method,the impact of temperature control valve on oil temperature was analyzed and the system transient temperature prediction method was established.This method could be used to predict the harmful temperature exceedence during engine operation.Only a small quantity of experimental data is necessary for the model fitting.The simulation results agree well with the test data.This approach can reduce the experimental cost, save experimental time and can be used to predict the oil cooling ability under severe operating conditions that experimental work is difficult to conduct.