In this paper，the low frequency of infrared brightness temperature of central-eastern Bayan Har block before and after the Wenchuan and Lushan earthquakes is extracted and analyzed by the wavelet method based on the remote sensoring infrared data from MODIS /TERRA． The results show that: (1) 5 sharply infrared brightness temperature increasing anomalies occurred 2 years ago before the Wenchuan MS8． 0 earthquake，while there was none of the same anomaly after the quake in 5 years until a new one appeared 2 months before the Lushan MS7． 0 earthquake． (2) In spatial，the high value abnormal region migrated towards Longmenshan fault zone gradually over time． (3) Only 2 of all the 6 anomalies are impending ones，which are from April to June，2008，and from February to April 19，2013，respectively． The sharply temperature increasing phenomenon in the central-eastern Bayan Har block may be the strong earthquake indicator of this region．