Abstract: In the report, the continuous spraying of Q235 steel for 1, 3, 7, 21, and 42 d with a neutral salt spray tank were performed to compare and analyze the macro/micro morphology changes, mass loss, surface strain field changes, and the degradation law of various mechanical properties （elastic modulus, yield strength, tensile strength, and strain after fracture） with the weight loss rate of Q235 steel after corrosion. The effects of the corrosion time on Q235 steel were also studied. The results showed that salt spray accelerated the formation and shedding process of the rust layer, the microstructure developed from sparse pitting to pitting, and then to honeycomb. The average corrosion rate decreased firstly, and then increased with the salt spray time. The mechanical properties had a linear relationship with the weight loss rate. With the extension of corrosion time, the high strain area became more dispersed, the surface strain field became more uneven, especially in the elastic stage and the strengthening stage. Salt spray reduced the strain difference at the fracture stage, and made the material brittle, and the macro fracture morphology changed from inclined fracture to step fracture.