To investigate the freeze-thaw resistance of composite limestone powder-fly ash-slag concrete, rapid freeze-thaw test and mercury compression test were conducted on concrete of three cementitious material systems at four different water to binder ratios. The degradation law of the freeze-thaw resistance was studied in terms of appearance damage, mass loss, relative dynamic elastic modulus and pore structure. The results show that: under the same conditions, the freeze-thaw resistance of concrete can be improved by appropriately reducing the water to binder ratio. Compared with ordinary concrete, the composite cementitious material system composed of mineral admixtures such as limestone powder, slag and fly ash and cement improves the freeze-thaw resistance of concrete. Because the activity of slag is higher than that of fly ash, "20% (mass fraction, the same below) limestone powder+15% fly ash+15% slag" concrete is weaker than "20% limestone powder+30% slag" concrete. The mineral admixture can refine the pore size of concrete and improve the freeze-thaw resistance. Through theoretical analysis and regression of experimental data, the freeze-thaw damage model of composite limestone powder-fly ash-slag concrete with different cementitious material systems was established.