A power supply chassis has at least one accommodating slot therein. Two side walls of the accommodating slot of the power supply chassis are provided with a first left guiding and fixing block and a first right guiding and fixing block. The guiding and fixing blocks have a first left guiding bevel and a first right guiding bevel facing a front side of the accommodating slot, a first left fixing plane and a first right fixing plane corresponding in position to the middle of the accommodating slot. When a power supply is placed into the accommodating slot, the first left guiding bevel and the first right guiding bevel guide the power supply to a middle position of the accommodating slot, and the power supply is clamped by the first left fixing plane and the first right fixing plane to enhance the stability of the power supply.