When building a basement parking garage, we need to pay attention to many issues to prevent fire and explosion, achieve ventilation to ensure human health, in which ventilation is the most important factor. The current difficulty of the basement parking garage problem is that the amount of natural wind is not enough to clear the air in the tunnel, the tunnel design is not the most effective to catch the wind in the natural direction, the cost is high when using the method. Forced ventilation, using a extractor fan consumes energy, on the other hand, a smart extractor fan costs a lot of money. Therefore, the purpose of this study is to simulate forced ventilation in basement parking garage by finite volume method, to solve the problem of computational fluid dynamics (CFD) based on Ansys program, to ensure that the important positions in the basement reach a certain level of comfort.