Abstract: The problem of strength deterioration of hydraulic concrete structures in salt lakes and saline soil areas in cold regions is outstanding. Based on the theory of isotropic continuous damage mechanics, the quantitative relationship between relative dynamic elastic modulus and relative compressive strength of concrete was presented. Next, a concrete strength evolution model under the synergistic action of sulfate erosion and freeze-thaw was proposed, and the model was verified. Finally, the model was applied to the verification and performance evaluation of Yindaruqin aqueduct over the Zhuanglang River. The research results show that the model can well simulate the strength evolution law of concrete subjected to salt frost erosion. Through numerical simulation analysis, it is found that the numerical results of the aqueduct are consistent with the operating conditions. With the deterioration time increasing, the maximum compressive stress and displacement of the aqueduct body increase, while the maximum tensile stress decreases. Salt freezing will accelerate the deterioration rate of the aqueduct, and the aqueduct would be damaged after 59.1 years of operation. The research results can provide a theoretical basis for performance evaluation and operation maintenance of hydraulic concrete eroded by salt freezing in cold and arid areas.