In the process of high speed sliding electrical contact, the contact surface will produce electric phenomenon such as joule heat, arc, etc., that will lead to contact temperature mutations. Temperature is one of the key factors of the materials′ conductivity and friction and wear. In order to measure the instant changes in temperature of high speed sliding contact, a transient temperature measurement method is proposed. A measurement system is designed based on the principle of infrared radiation in view of the high voltage and large current environment. This system contains optical fiber temperature measuring probe, isolation module and high-speed data acquisition module. Calibration experiment is performed with blackbody furnace, and verification experiment on the performance of the system is performed in the high-speed sliding experimental machine. The results show that the system′s effective temperature range for non-contact measurement can be 600 ℃~2000 ℃, and it has high accuracy and short response time. It is suitable for transient high temperature measurement such as the special environment of high speed sliding electrical contact.