The invention provides a preparation method of a high-strength heat resistant and corrosion resistant stainless steel wave key. Nickel, chromium and manganese are placed into a feeding port of a vacuum die-casting machine by mass percentage, and are melted into melt in a melting device; cut small block 304 stainless steel plates and the melt are injected into an extruding mold together; and the formed wave key is obtained after extruding forming. The preparation method aims at the problems existing in an existing offshore oil and gas storing and transporting device lock, the wave key is produced and machined by utilizing a number 304 stainless steel material, an offshore oil and gas storing and transporting device is restored, the original mechanical performance of equipment is guaranteed,the equipment is enabled to have certain corrosion resistance, the restoration period is short, and cost is low.