A lateral power semiconductor device includes a first type doping substrate at a bottom of the lateral power semiconductor device, a second type doping drift region, a second type heavy doping drain, a first type doping body; a first type heavy doping body contact and a second type heavy doping source, where dielectric layers are on a right side of the second type heavy doping source; the dielectric layers are arranged at intervals in a longitudinal direction in the first type doping body, and between adjacent dielectric layers in the longitudinal direction is the first type doping body; and a polysilicon is surrounded by the dielectric layer at least on a right side. Compared with conventional trench devices, the lateral power semiconductor device introduces a lateral channel, to increase a current density, thereby realizing a smaller channel on-resistance.