The ignition temperature and the diffusion combustion conditions of TC4 titanium alloy were studied under the simulated compressor environment by the friction tests. The temperature and distribution characteristics of the combustion process were calculated by the finite element method. It was shown that rubbing rings of rotors were first burned, which dependedSon the heat accumulation of stators. For the first time, the ignition temperature(1266.47℃) of TC4 titanium alloy under the simulated compressor environment was obtained, and the error between the measured temperature and the ignition temperature(1210℃) calculated by the finite element method was just 3.6%. The stator began to burn when its total heating areas of cross section reached 25% and its areas of high temperature between 932℃ and 1210℃ were 3.06%.