The invention discloses aluminum steel hot melting welding flux. The aluminum steel hot melting welding flux comprises aluminum powder, ferric oxide, alloy additives and a slag former. The aluminum steel hot melting welding flux is characterized in that the aluminum steel hot melting welding flux contains abrasive grits with the diameter being 2-3 mm and the length being 5-6 mm. Compared with existing hot melting welding flux, raw materials of the aluminum steel hot melting welding flux are easy to obtain, the cost is low, the formula is simple, and operation is convenient; the aluminum steel hot melting welding flux is adopted for welding, so that the welding quality is good, the ignition efficiency is high, the connection surface is smooth, the contact resistance is small, the extension strength is large, and the filling metal amount can be decreased. A metallurgy reaction is sufficient, and the probability of existence of defects such as pores and cracks is lowered. In addition, no external power source is needed during welding of the aluminum steel hot melting welding flux, the welding quality is stable and reliable, and the aluminum steel hot melting welding flux has the remarkable economic benefits when used for anode rod and steel claw welding.