In order to elucidate the mechanism of formation of thaumasite from concrete prepared by lime powder under sulfate environment at low temperature, cement based materials made by limestone powder concrete and sulphoaluminate cement were immersed in magnesium sulfate and sodium carbonate solution at 10% mass fraction. The compressive strength was measured, and the microstructure of thaumasite was analyzed by SEM, XRD and infrared spectroscopy. The results show that after soaking in MgSO4 solution at low temperature, the limestone powder concrete occurs flaking phenomenon. The compressive strength increases at first and then decreases with the increase of immersion time. The specimen surface generates a large amount of gypsum due to expansion corrosion. Sulphoaluminates cement based materials with mud can be seen after soaking in Na2CO3 solution, and its compressive strength decreases with the increase of immersion time. Ettringite, the internal hydration product, gradually decreases with the production of heterogeneous silicate crystal and transformation into thaumasite. Mixing limestone powder in concrete is not the main factor to cause TSA(thaumasite sulfate attack)type corrosion. Etrringite in the hardening body of cement based materials in environment containing with carbonate ions for a long time will generate a large amount of sludge like thaumasite and results in damage to the cementitious materials.