[Purposes] Aiming at the durability of construction solid waste recycled aggregate CFG piles (Cement Fly-ash Gravel) under the environment of water immersion and salt ion erosion, to reveal the deterioration law of its material performance, and to provide theoretical support for engineering applications.[Methods] Based on the actual engineering environment, two erosion experiment simulation conditions are set: immersion water and salt ion erosion. Taking the recycled aggregate CFG pile specimen as the test object, and the control group as the modified aggregate CFG pile specimen and natural aggregate CFG pile specimen under the same conditions, we quantitatively analyze the change rule of performance before and after the erosion through the water absorption rate test and compressive strength test. Based on the test data, the time-varying prediction model of water absorption and compressive strength under the submerged environment and compressive strength under sulfate erosion was established.[Findings] Under long-term water immersion condition, the water absorption rate of recycled aggregate CFG pile shows the change process of rising firstly and then tends to stabilize after immersion time, and the water absorption rate of the test block stabilizes at about 3.1% in 60 days, which is significantly higher than that of modified aggregate CFG pile and natural aggregate CFG pile, and the stabilization period is extended by 40%-50%; its compressive strength shows the trend of “increasing firstly and then decreasing”, and the maximum decrease is 10.5%. Its compressive strength shows a trend of “first increase and then decrease”, with a maximum decrease of 10.5%. In the salt ion erosion environment, its compressive strength is increased by the pore filling strength of calcium alumina in the early stage (+4.74%, +8.51%, +13.18% under weak/medium/strong sulfate erosion, respectively), and then accelerated deterioration due to the expansion and cracking in the later stage, and the strength decrease is positively correlated with the sulfate concentration.[Conclusions] Recycled aggregate CFG piles have the potential for solid waste resource utilization, but their porous structure leads to high water absorption, significant sensitivity to sulfate erosion, and can accommodate expansion products at the initial stage, with short-term strength gain better than that of CFG piles with natural aggregates, but the strength plummets due to crack expansion in long-term service, and the pore structure needs to be optimized through modification to enhance durability.