The invention provides a trench gate power FET (Field Effect Transistor). The trench gate power FET comprises a source electrode layer, a drain electrode layer, a doped trap layer and a gate electrode, wherein the source electrode layer is arranged on a first surface of a substrate, and the drain electrode layer is arranged on a second surface, which is opposite to the first surface, of the substrate; the doped trap layer is arranged between the source electrode layer and the drain electrode layer and is attached to the source electrode layer and the drain electrode layer, the source electrode layer and the drain electrode layer are provided with first conduction types, and the doped trap layer is provided with a second conduction type; the first surface of the substrate is further provided with a trench, a gate dielectric layer covers the inner wall of the trench, and the gate electrode is arranged in a space surrounded by the gate dielectric layer; the doped trap layer comprises a heterojunction formed by Si(1-x)Gex/Si in a direction vertical to the surface of the substrate. The trench gate power FET provided by the invention has the advantages that the energy band structure of the heterojunction can be regulated by regulating the mole percentage of Ge, and the optimization of a device can be realized.