In order to investigate the effect of freeze–thaw cycles on the damage characteristics of mixed mode I-II crack propagation in concrete. The three-point bending and three-point shear fracture test were carried out on specimens subjected to different freeze–thaw cycles (0, 50, 100, 150 and 200). The analytical expression of mixed mode I-II damage scale r0(I,II) and ru(I,II) was derived, and the effect of freeze–thaw cycles on damage scale was analyzed. In addition, the critical damage scale of mixed mode I-II fracture was obtained using the numerical simulation method, and the simulation results were compared with the calculation results. Finally, the accumulate energy and tension-shear failure of concrete after freeze–thaw cycles were analyzed based on acoustic emission technology.