Technical method for preparing SOI LDMOS device

The invention relates to a technical method for preparing an SOI LDMOS device. The method comprises the following steps: (1), performing P-type trap injection in a top-layer silicon film; (2), applying an oxidation backflow technology on the top-layer silicon film; (3), using a photoetching technology; (4), employing the photoetching technology and a corrosion technology; (5), utilizing the oxidation backflow technology;(6), employing the corrosion technology; (7), performing N-type trap injection to form an N-type doped area; (8), performing the P-type trap injection to form a first P-type doped area; (9), performing the P-type trap injection to form a second P-type doped area; (10), performing P-type source-drain injection to form a P-type source area and a P-type drain area; (11), performing deposition to form an insulation medium layer; (12), carrying out photoetching corrosion; (13), performing deposition to form a metal layer; (14), and carrying out the photoetching corrosion. The technical method is compatible with a CMOS technical process, the technology is concise and controllable, voltage withstanding performance of the high-voltage SOI LDMOS device can be ensured, and at the same time, isolation between devices can also be ensured.