A VDMOS device and a manufacturing method therefor. The manufacturing method comprises: forming a groove in a semiconductor substrate, the groove comprising a first groove area, a second groove area, a third groove area, a fourth groove area and a fifth groove area; successively forming a first insulation layer, a first polycrystalline silicon layer and a second insulation layer on the semiconductor substrate; removing some of the second insulation layer until the first polycrystalline silicon layer is exposed; removing some of the first polycrystalline silicon layer, the remaining first polycrystalline silicon layer forming a first electrode; forming a third insulation layer on the semiconductor substrate, removing some of the third insulation layer, the second insulation layer and the first insulation layer, so that the top of the first polycrystalline silicon layer is higher than the top of the first insulation layer and the second insulation layer; and successively forming a gate oxide layer and a second polycrystalline silicon layer on the semiconductor substrate, and removing some of the second polycrystalline silicon layer, exposing the gate oxide layer located on the surface of the semiconductor substrate and the top of the second insulation layer, the remaining second polycrystalline silicon layer forming a second electrode.