Protection method for preventing seizure of high-temperature threaded fastener

The invention discloses a high-temperature threaded fastener anti-seizure protection method, and relates to the field of threaded fastener anti-seizure, and the method comprises the following steps: S1, cleaning the surface of a threaded fastener to make the surface of the threaded fastener smooth; s2, a coating system is selected according to the service environment of the threaded fastener; the hard nitride coating is prepared on the smooth surface of the threaded fastener through the physical vapor deposition technology, the hard nitride coating structurally comprises a metal priming coat and a functional layer based on a CrN coating system or a CrAlN coating system in sequence from bottom to outer, and the functional layer is of a single-layer structure or a multi-layer structure. The compact hard nitride coating is prepared on the surface of the smooth threaded fastener, so that the oxidation resistance, wear resistance and corrosion resistance of the material surface are improved, and the seizure risk o