The influence mechanism of temperature, Cl^-, and on the electrochemical behavior of Q235B steel in the early stage of corrosion was studied through complete factorial experiments using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP), combined with statistical analysis. The results indicate that an increase in temperature significantly reduced the charge transfer resistance (R_ct) and accelerated the corrosion process, with its mechanism mainly related to mass transfer processes. The increase in Cl^- and content significantly increased the solution resistance and the effect of the constant phase angle element (biased Eta>0.5), indicating that these ions affected the electrochemical reaction kinetics by enhancing interfacial conductivity. In addition, Cl^- was negatively correlated with interfacial capacitance (r=-0.28), while was positively correlated (r=0.44). This indicated that might interact with Cl^- and inhibit corrosion at certain concentrations.