A VDMOS device and a manufacturing method therefor. The method comprises: forming a groove in a semiconductor substrate, wherein the groove comprises a first groove area, a second groove area and a third groove area communicating with the first groove area and the second groove area, and the width of the first groove area is greater than the widths of the second groove area and the third groove area; forming an insulation layer on the semiconductor substrate; forming a first polycrystalline silicon layer on the insulation layer; removing some of the first polycrystalline silicon layer; the first polycrystalline silicon layer forming in the first groove being used as a first electrode of a deep gate; removing all the insulation layer located on the surface of the semiconductor substrate and some of the insulation layer located in the groove; forming a gate oxide layer on the semiconductor substrate; forming a second polycrystalline silicon layer on the gate oxide layer; removing some of the second polycrystalline silicon layer; and the second polycrystalline silicon layer forming in the groove being used as a second electrode of a shallow gate.