To improve the aerodynamic performance of a small forward curved centrifugal fan, the centrifugal fan used for car seat ventilation was taken as the research object in this paper. The effects of the number of blades, the blade outlet angle, the blade inlet angle, and the blade thickness on the aerodynamic performance of the centrifugal fan were studied by means of combining numerical simulation and an orthogonal experiment. The experiment used a small air volume fan performance test bench to validate the numerical simulation results. Three-level orthogonal table L9（34） was selected to arrange the test, and impeller models with nine different parameter combinations were established. The optimal centrifugal fan parameter combinations were obtained by using the computational fluid dynamics method with maximum static pressure as the optimization objective. In addition, the pressure and velocity distribution in the centrifugal fan before and after optimization were compared and analyzed. According to the direct analysis of the orthogonal test results, it can be seen that the influence of each parameter on the maximum static pressure of the centrifugal fan is in the order of the blade outlet angle, the blade inlet angle, the number of blades and the blade thickness. In addition, the maximum static pressure can be achieved by the following parameters: the number of blades of 55, the blade inlet angle of 95°, the blade outlet angle of 125°, and the blade thickness of 0.8 mm. The dimensionless characteristic curve of the optimized fan is better than that of the original fan, and the static pressure can be increased by 3.78%~10.67% in a high-efficiency area. Compared with the pressure and velocity distribution of the flow field inside the centrifugal fan before and after optimization, the distribution of the flow field inside the optimized centrifugal fan is more uniform, the pressure in the low-pressure area at the impeller inlet is lower, and the velocity is higher, which is more conducive to the flow into the centrifugal fan.