In order to study the freeze-thaw resistance of iron tailings sand foam concretefive groups of foam concrete with a target density of 900 kg/m3 were prepared. The mass lossstrength losspore area rate and microstructure of foam concrete with different iron tailings sand content after freeze-thaw cycle in sulfate environment were compared and analyzed. Taking the mass loss and strength loss as the measurement indexesthe optimal mix ratio was selectedand the reliability analysis and residual life prediction were carried out based on the Wiener degradation process. The results show that during the sulfate freeze-thaw cyclethe surface of foam concrete is damagedthe internal pores are connected to form cracksand the mass of each specimen increases first and then decreases. The compressive strength and pore area rate continue to declineand the addition of fine iron tailings sand effectively alleviates the damage of foamed concrete. Among themthe foam concrete with 20% (mass fraction) iron tailings sand content has the strongest freeze-thaw resistanceand the specimen fails after about 300 freeze-thaw cycles. This study can provide ideas for the application of foam concrete in frozen soil areas.