Abstract: This paper focuses on adding different concentrations sulfonated polyaniline in sodium molybdate (SPAN)/calcium bentonite composites for the accelerated corrosion test. The corrosive macro and micro morphology and corrosion rate, protection degree calculation of Q235 was characterized by XRD, SEM corrosion-test respectively. It was used to evaluate the influence of sodium molybdate on corrosion of (SPAN)/calcium bentonite composites. The results show that corrosion resistance of SPAN/calcium bentonite composite can be reduced by adding sodium molybdate. It has great influence on the corrosion morphology and corrosion rate of SPAN/calcium bentonite composite based on different concentrations of sodium molybdate. When the mass fraction of molybdate is 1.5%, composites can be formed into a compact protective film layer on the surface of Q235 which is composed of MoO₃、FeMoO₄、Fe₂O₃. They greatly inhibited the corrosion of Q235, and the corrosion rate is the lowest. Its protection degree of Q235 is up to 70.76%.