Abstract: The damage of composite materials poses a threat to the reliability and safety of the structure, and has attracted widespread attention from domestic and foreign experts and scholars in recent years. This study embeded the shape memory alloy (SMA) in the composite material specimen, and discussed the relationship between the SMA resistance change and the composite material strain, established theoretical models of composite damage monitoring under different monitoring conditions. Based on this model, the damage monitoring behavior of SMA materials in different initial states was discussed. The research results show that the damage of the composite material has a linear relationship with the resistance change of the SMA. The temperature load has little influence on the damage monitoring when the SMA does not undergo a phase change, and has a greater influence on the damage monitoring when the SMA undergoes a phase change. The research can provide theoretical guidance for the further engineering application of SMA-based composite damage monitoring theory.