A military electric heater is an electric heating device that primarily heats a gas stream. The heating element is a stainless steel electric heating tube, and a plurality of baffles (baffles) are arranged in the inner cavity of the heater to guide the gas flow direction, prolong the residence time of the gas in the inner cavity, thereby fully heating the gas, heating the gas evenly, and improving Heat exchange efficiency. The heating element stainless steel heating tube is formed by charging a heating wire into a seamless steel pipe, and filling the gap portion with a magnesium oxide powder having a good thermal conductivity and insulation. When the current passes through the high temperature resistance wire, the generated heat is diffused to the surface of the heating tube by the crystalline magnesium oxide powder, and then transferred to the heated gas to achieve the purpose of heating.