The invention related to a multi-functional power tool, comprises an housing, a motor set in the housing, a main shaft driven through the rotation of the motor, a working shaft extended outside the housing, an active impact block, which can rotate with and make axial motion with respect to the main shaft, is configured on the main shaft, a passive impact block which rotates with the working shaft and can alternatively make axial motion with respect to the working shaft is mounted on the working shaft, the active impact block rotates to drive the passive impact block through the coordination of the first end tooth set on the active impact block and the second end tooth set on the passive impact block; the power tool further includes a function shifting button which can move between the first location and the second location to alternatively limit the passive impact block's axial motion with respect to the working shaft, in this way to realize the shifting between the first function and the second function of the power tool. This function shifting mechanism features simple structure, low manufacturing cost, convenient and efficient operation.