Objective To improve the properties of corrosion resistance of steel Q235. Methods The quenching heat treatments were performed with simulated water quench process on steel Q235 after adding ZnSO4 inhibitor medium. The steel Q235 was characterized and tested by XRD testing, atmospheric corrosion, and electrochemical tests (including polarization curves and AC impedance) under different solutions. Results Fe2O3, Fe3O4 and Zn(OH)2 protective films were generated on the sample surface. When the amount of corrosion inhibitor ZnSO4 reached 120 mg/ L, the corrosion rate was reduced to 0. 2083 g/ (d·m2) from 0. 4583 g/ (d·m2) in the water quenching. The rebar corrosion rate was reduced by 54. 5% . The corrosion potential increased from -0. 3752 V to -0. 2997 V of Q235, the corrosion potential increased by 20. 1% , the corrosion current reduced from 5. 2482×10-5 A to 1. 6082×10-5 A, the corrosion current was reduced by 69. 3% , the capacitance spectrum value Rr increased from 25. 58 Ω up to 32. 52 Ω which was increased by 27. 1% . The polarization of Q235 in simulated rain was the form of electrochemical polarization. Conclusion ZnSO4 inhibitor can effectively alleviate Q235 steel corrosion resistance.