Theory analyze the creep property of film in fluctuating temperature conditions. A numeric model is established basing on ANSYS software with taking WC-6%Co as substrate and (Ti,Al)N as film. The degradation rule of temperature field and stress field with the increasing and decreasing film's temperature are analyzed. The calculated results show that: in the fluctuating temperature conditions, the function of stress creep can be derivated by the one of stress creep curve under the history temperature of constant temperature. And the compress stress increases with the increasing of temperature, the tensile stress is produced with the decreasing of temperature. The size of tensile stress in the direction of normal axis is three times as big as optical axis. The fracture of film probably happens more than that of spall.