Abstract: Cryopump is the most important equipment to obtain high vacuum for KM6 The temperature variation on the second level cryohead has a direct effect on cryopump’s vacuum, therefore it is important to monitor the temperature variations inside cryopump extensively and accurately for stable operation of the pump. This paper discusses the development of related software and hardware, the selection of measurement components, their installations, and the system test. The new system has been used for thermal vacuum test successfully in providing useful data, as are essential for fault analyses.