Provided are a laterally diffused metal oxide semiconductor field-effect transistor and a manufacturing method therefor. The method comprises: providing a wafer on which a first N well (22), a first P well (24) and a channel region shallow trench isolating structure (42) are formed; forming a high-temperature oxidation film on the surface of the wafer by deposition; photoetching and dryly etching the high-temperature oxidation film, and reserving a thin layer as an etching buffer layer; performing wet etching, removing the etching buffer layer in a region which is not covered by a photoresist, and forming a mini oxidation layer (52); performing photoetching and ion injection to form a second N well (32) in the first N well and form a second P well (34) in the first P well; forming a polysilicon gate (62) and a gate oxide layer on the surface of the wafer; and photoetching and injecting N-type ions to form a drain electrode (72) and a source electrode (74).