In order to explore the degradation law of mechanical properties of steel strands in prestressed concrete beams after corrosion in acid rain environment, the static performance and fatigue performance of corroded steel strands were systematically studied by means of experiment and simulation. A total of 22 post-tensioned prestressed concrete beams were poured in the test. The specimens of steel strands with corrosion rates of 0 %, 1 %, 3 % and 5 % were prepared by electrochemical accelerated corrosion method (sulfuric acid simulated acid rain solution with pH=3.0). The corroded steel strand samples were taken out from the broken concrete. Among them, 12 were subjected to static tensile test and 10 were subjected to axial tensile fatigue test. The test results show that the combined effect of stress and corrosion leads to a significant reduction in the ductility of the material. When the corrosion rate reaches 5 %, the maximum yield strength decreases by 23.14 %, the maximum ultimate strength decreases by 30.41 %, and the elastic modulus decreases by 26.67 %. The fatigue life of corroded steel strands is significantly reduced. Under the same stress amplitude, the attenuation rate of fatigue life of steel strand decreases with the increase of corrosion rate. At the same corrosion rate level, the fatigue life and stress amplitude of steel strands are linear in the double logarithmic coordinate system. In addition, the test results were simulated and verified by combining ABAQUS and FE-SAFE fatigue simulation software, and a fatigue life prediction model for steel strands considering the combined effect of corrosion rate and stress amplitude is proposed. In addition, the test results are simulated and verified by ABAQUS and FE-SAFE fatigue simulation software, and a fatigue life prediction model of steel strand considering the combined action of corrosion rate and stress amplitude is proposed. The prediction error is kept within 10 %, and the data are in good agreement. The research results can provide a theoretical basis for the durability design and residual life evaluation of prestressed concrete structures under acid rain environment.