Thermite welding is a track connection construction process with mature technology, simple, convenient, fast, and high-quality construction.Rail thermite welding is the thermite flux composed of aluminum powder, iron oxide and other metal additives in a special crucible, and a high temperature match is used to ignite the thermite reaction. During the reaction, a large amount of heat is released and the molten alloy mixture reacts to form.Because of its high density, molten steel sinks below, the slag generated by the reaction is relatively light and floats on the upper part, and the molten steel is filled with sand in a short time.At the same time, the aluminum hot molten steel itself acts as a filler metal, crystallizes and cools together with the molten steel rail, and the two steel rails form a whole.