Taking the ancient building wall of Longshengzhuang in Inner Mongolia as the research object， the damage and failure law of ancient building blue bricks under freeze-thaw cycles were investigated by digital image correlation（DIC） technology. Two-factor—damage degree factor and damage localization factor were used to characterize the uniaxial compression damage process of ancient building blue bricks. Based on the two-factor damage evolution curve， a damage evolution model was established under different freeze-thaw cycles. The results show that the failure process of ancient building blue bricks under uniaxial compression can be divided into four stages—initial damage closure stage， linear elastic damage stage， elastic-plastic damage stage and plastic damage stage. With the increase of freeze-thaw cycles， the strain concentration on the surface of blue brick increases， resulting in a decrease in bearing capacity. Freeze-thaw cycles will shorten the linear elastic stage in the two-factor curve. At the same time， the damage evolution model established by the two-factor can effectively reflect the damage evolution process of the ancient building blue brick material under the action of freeze-thaw cycles.