The invention relates to a power device which can provide power for tool main bodies of electric tools. Each tool main body comprises a tool shell and a working part. The power device comprises a main shell, a motor supported by the main shell and an energy providing unit providing energy for the motor. The power device can be detachably connected with the tool main bodies. When the power device is connected with the tool main bodies, the main shell is supported by the tool shells. The power device can be commonly used for different tool main bodies, therefore, the universality of the power device is improved, and the using cost is lowered for users.