Abstract: To study the interaction of the cooling air system of armored vehicle structure and performance parameters, the paper presents an effective one dimensional computational fluid dynamics (CFD) simulation method to build up a powertrain compartment. The one dimensional CFD simulation model of the powertrain compartment is created by utilizing performance experimental data of main components, and the main design parameters of the cooling air system including the structure parameters of wind tunnel, the resistance of wind tunnel, the cooling airflow rate and the power of fan are forecasted and optimized. The results indicate that the effect of the structure parameters of wind tunnel variation on the performance of the cooling air system is small when <em<h</em< varies between 125 and 214mm and <em<L</em< varies between 100 and 200mm at the same time, meets demands restriction in the whole space of powertrain compartment.