Considering the shortage of natural sand and the environmental crisis caused by waste concrete, recycled fine aggregate (RFA) with different replacement rates was used to prepare recycled fine aggregate concrete (RFAC), the evolution law of RFAC performance under dry-wet cycle was analyzed, and chloride ion erosion resistance of RFAC was studied. The results show that the compressive strength of concrete is reduced by the addition of RFA. The 28 d compressive strength of RFAC with RFA mass replacement rate of 100% is 77.0% of ordinary concrete. The free chloride ion content of RFAC increases first and then decreases and finally stabilizes with the increase of erosion depth under the dry-wet cycle. The convection zone and diffusion zone of chloride ion appeares obviously, and the depth of the convection zone is about 5 mm, and the depth of the convection zone also increases with the increase of the dry-wet cycles times and the RFA replacement rate. The porosity of RFAC increases exponentially with the increase of dry-wet cycles times. The porosity of concrete with high RFA replacement rate increases more obviously under dry-wet cycle, which is the reason why its chloride ion erosion resistance becomes worse.