Shield grid power MOSFET device

The invention provides a shield gate power MOSFET device, which is characterized in that a groove structure is formed by growing an oxide layer and etching again, a structure in which the bottom of a groove is surrounded by a second conductive type doped region is formed by adopting a multi-time epitaxy and ion implantation mode, and meanwhile, the second conductive type doped region is led out; through connection with the shield grid or the second conductive type well region, the problem of dynamic resistance is eliminated, the problem of device performance degradation caused by too many defects at the bottom of the groove is solved, and the reliability of the device is improved; besides, the first conductive type heavily doped region and the second conductive type heavily doped region are arranged in a crossed manner, and a CT small hole is changed into a whole active region large hole, so that physical damage to a channel region caused by plasma etching under the condition of small size is avoided, and the