The work aims to improve corrosion resistance of steel materials to LBE by preparing micro-arc oxidation ceramic layer with Q235 steel as substrate. 1.5 mm thick 5A06 aluminum alloy and 3 mm thick galvanized Q235 steel were welded by TIG welding-brazing combined with the ER4043 filler metal. The annealing treatment was carried out to the joints at 280 ℃ for 30 min after welding. Meanwhile, micro-arc oxidation ceramic coatings were prepared on the surface of aluminum/steel weld seam by suitable micro-arc oxidation process in order to investigate the effect of micro-arc oxidation treatment on the corrosion resistance of steel materials to LBE. The intermetallic compound layer was inevitably formed at the interface between aluminum and steel, when the aluminum alloy and steel were welded by TIG welding-brazing. The thickness of the intermetallic compound layer reached 9~10 μm after the joint by aluminum/steel welding-brazing was annealed at 280 ℃ for 30 min. The compound layer consisted of Al8Fe2Si phases and a little [Al, Fe, Si] and Al13Fe4 phases. The tensile strength of joint was 185 MPa and the ductile fracture occurred in aluminum base metal. Uniform ceramic coatings could be formed on weld surface by micro-arc oxidation treatment. Volcano-like morphology with many micro pores could be observed on the surface of ceramic coatings and there were many discharge pores with different sizes at the center of volcanic substance. In addition, the ceramic coatings with low surface roughness were composed of α-Al2O3, γ-Al2O3 and mullite phases mainly. Many corrosion pits were found on the surface of Q235 steel after corrosion, and lots of Pb and Bi elements diffused into the steel material. However, there were no obvious corrosion phenomenon on the surface of ceramic coatings after corrosion. Micro-arc oxidation treatment can improve the corrosion resistance of steel materials to LBE and hinder the diffusion of Pb and Bi elements into the steel material.