In chloride corrosion environment, steel bar corrosion is one of the main reasons for the degradation of concrete structure durability. In order to improve the long-term performance of concrete structures and extend the service life of concrete structures, the mechanical properties and long-term corrosion behavior of new stainless steel clad rebar were studied using uniaxial tension and electrochemical test methods. The results show that the stainless steel clad rebar combines the excellent properties of stainless steel and carbon steel. The yield strength is improved to varying degrees compared with HRB400E carbon steel bars and solid stainless steel bars. The ductility is smaller than that of solid stainless steel but close to that of HRB400 steel bars. The elastic modulus is slightly lower than that of HRB400E steel bars. Under the action of chloride salt corrosion, stainless steel clad rebar is mainly pitted, and the corrosion products contain more α-FeOOH which makes the rust layer denser than that of HRB400E steel bars. Solid stainless steel bars have the best corrosion resistance, HRB400E has the worst corrosion resistance. And the corrosion resistance of stainless steel clad rebars is between solid stainless steel bars and HRB400E. The yield strength, ultimate strength and elongation after fracture of the corroded stainless steel clad rebars all decrease to varying degrees with the increase of the corrosion rate. Based on experimental research and theoretical analysis, the stress-strain constitutive model of stainless steel clad rebars and the relationship between the strength and elongation after fracture of stainless steel clad rebars after corrosion and the corrosion rate were established.