The invention discloses a flame preheating plug and a preparation method thereof. The preparation method comprises the steps that 1, raw materials are subjected to die casting to obtain an embryonic form of the flame preheating plug; 2, the embryonic form of the flame preheating plug is subjected to surface polishing; 4, the polished embryonic form of the flame preheating plug is washed with water; 4, the washed flame preheating plug is placed in an electroplating pool for surface electroplating, and the flame preheating plug is obtained, wherein a plating of surface electroplating is one of a copper layer, a chromium layer and a nickel layer. The raw materials are subjected to surface polishing after die casting, then water washing is carried out, the surface of the washed flame preheating plug is electroplated with the copper layer or the chromium layer or the nickel layer, and therefore the flame preheating plug prepared through the method can be prepared through common raw materials, and good use performance can be achieved.