Lateral high-voltage device

The invention provides a lateral high-voltage device. The lateral high-voltage device comprises a dielectric groove region; the dielectric groove region comprises a dielectric groove area on the lower part and a low-K dielectric groove in the upper part; the lateral high-voltage device also comprises a dielectric layer, a body field plate, a polysilicon gate, an under-gate oxide layer, a dielectric layer, a drain contact electrode, a first N type heavily doped region, a second N type heavily doped region, source metal, a P type heavily doped region and a P well region; conductive paths formed by first, second and third N type doped strips are formed in the two sides and the bottom of the dielectric groove region respectively; P type doped regions are arranged on the two sides of the conductive paths respectively; and a P type substrate is arranged at the bottoms of the conductive paths. By introducing the dielectric groove region into a drifting region, the voltage withstand of the device is maintained while