The electromechanical impedance (EMI) method is one of the hot research fields of structural health monitoring (SHM) technology. However, in practical applications, the impedance signal measured by EMI method will be disturbed by temperature, resulting in misjudgment of damage. Firstly, the reason for the change of impedance caused by temperature is analyzed theoretically. Then, taking the typical PZT-5H ceramic sensor in EMI method as the research object, the influence of temperature on the characteristics of PZT impedance is tested and analyzed. It is found that the frequency shift of impedance peak is linear with temperature, and the influence of temperature on the peak frequency shift is closely related to frequency. Further, combined with the variation law of frequency offset and amplitude, the temperature effect correction model of structural health monitoring based on the mechanical impedance method is established. The results lay a foundation for reducing the influence of ambient temperature on the impedance characteristics of PZT.