Semiconductor power device and preparation method thereof

The invention discloses a semiconductor power device and a preparation method thereof, the semiconductor power device comprises JFET regions located in a drift layer between adjacent well regions, the JFET regions comprise a first JFET region and second JFET regions located between the first JFET region and the well regions, the second JFET regions at the two sides of the first JFET region are arranged at intervals, the doping concentration of the second JFET regions is greater than the doping concentration of the drift layer, and the first JFET region and the second JFET region are located between the first JFET region and the well regions. The doping concentration of the first JFET region is smaller than that of the drift layer, or the first JFET region is electrically neutral; the second JFET region is provided with a first side wall and a second side wall which are arranged in the length direction of the channel region and are opposite to each other, the first side wall is in contact with the side wall of