Semiconductor power device and preparation method thereof

The invention provides a semiconductor power device and a preparation method thereof, and the device comprises a plurality of first doped layers which are arranged at intervals, are located in a drift layer at two sides of a gate structure along a first direction, and are located at one side, facing a semiconductor substrate layer, of a well region, the first doping layer is in contact with the well region and is spaced from the gate structure, and the doping type of the first doping layer is opposite to that of the drift layer; the spacing distance between the first doping layer and the semiconductor substrate layer is smaller than the spacing distance between the gate structure and the semiconductor substrate layer. And the width size of the surface of one side, facing the semiconductor substrate layer, of the first doping layer along the first direction is greater than or equal to the width size of the surface of one side, deviating from the semiconductor substrate layer, of the first doping layer along th