The invention discloses and a manufacture method of a laterally-diffused metal oxide semiconductor device. The method comprises the following steps: growing an oxide layer on a substrate of a wafer; coating photoresist on the surface of the wafer; carrying out photoetching by utilizing a first photoetching mask plate, and exposing a first injection window after developing; carrying out ion injection through the first injection window and forming a drift region in the substrate; coating a layer of photoresist on the surface of the wafer again after photoresist removing; carrying out photoetching by utilizing a drift region oxide layer photoetching mask plate; and carrying out etching on the oxide layer and forming a drift region oxide layer. The invention also relates to the laterally-diffused metal oxide semiconductor device. According to the method in the invention, the drift region oxide layer is grown first, and then, drift region injection is carried out, thereby preventing the problems of high on-resistance and thin concentration in laterally-diffused region of the drift region injection irons due to thermally growing the drift region oxide layer; and the irons with relatively-high concentration is directly injected to the region, thereby effectively reducing the on-resistance.