A technical method for LDMOS device buried layer

The invention discloses a technical method for an LDMOS device buried layer. The technical method includes: a first step in which, on a silicon substrate, an N-type buried layer area is defined by a photoresist, and on the outer circumference of the N-type buried layer area, one or a plurality of N-type ring-shaped buried layer areas surrounding the N-type buried layer area are defined; a second step in which an N-type buried layer is implanted, and impurities enter the silicon substrate through an N-type buried layer area window and an N-type ring-shaped buried layer area window which have been opened by lithography, so that the N-type buried layer area and the N-type ring-shaped buried layer area are formed; a third step in which high-temperature propulsion is performed; a fourth step in which generic implantation of P-type impurity ions is performed, so that a P-type buried layer is formed. The technical method of the invention does not add lithographic layers, continues to adopt the method of P-type buried layer generic implantation, adjusts the concentration on the edge of the N-type buried layer, and increases breakdown voltage of the LDMOS device.