This document stipulates the principle, materials and specimens, instruments and equipment, test conditions, test steps, test data processing, instrument calibration, and test report contents of the thermal interface material contact thermal resistance test method using the photothermal radiation method. This document is applicable to the measurement of contact thermal resistance between thermal interface materials such as thermal grease, thermal gel, and thermal pads and their bonding surface materials. Other types of thermal interface materials can be used with reference to this document.