Provided is a manufacturing method for a laterally diffused metal oxide semiconductor device, comprising the following steps: growing an oxide layer on a substrate of a wafer (S210); coating a photoresist on the surface of the wafer (S220); performing photoetching by using a first photoetching mask, and exposing a first implantation window after development (S230); performing ion implantation via the first implantation window to form a drift region in the substrate (S240); coating one layer of photoresist on the surface of the wafer again after removing the photoresist (S250); performing photoetching by using the photoetching mask of the oxide layer of the drift region (S260); and etching the oxide layer to form the oxide layer of the drift region (S270). Further provided is a laterally diffused metal oxide semiconductor device.