A computer housing, comprising a base plate and a rear plate, a main board is installed on the base plate, an expansion card is extended and connected to the main board, a power supply is installed on the rear plate, the rear plate An opening is opened on the top, the power supply includes a wider fan installation part and a narrower power supply installation part, a fan is installed in the fan installation part, and the fan installation part includes opposite rear walls and A first front wall, a number of openings are opened on the back wall, a number of first ventilation holes are opened on the first front wall, and the power supply installation part includes a second side perpendicular to the first front wall wall, the first front wall protrudes from the second side wall, the rear wall is installed in the opening, and the second side wall is opposite to the expansion card to form a wind between them. The first front wall is located in the air channel, and the fan can drive airflow to flow through the air channel to dissipate heat for the expansion card.