This paper introduces a transient temperature measurement system based on the colorimetric method in order to solve the problems of destroying the temperature field, device wiring inconvenience and needing to recover the readings in the conventional contact temperature measurement. The system is mainly composed of optical system, two-quadrant detector, optical amplifying circuit and single-chip microcomputer STM32. The wireless data transmission module is designed by using the single-chip microcomputer STM32 to ensure the real-time transmission of the experimental data and the real-time display of the measured temperature, thus the impact of the measurement environment is greatly weakened and the ease of use of the system is improved. The transient temperature experiment is carried on in the laboratory and the experimental results are compared with the infrared thermometer. In the experiment, six time nodes are selected to compare the test results. Through the analysis of the experimental results, the relative errors of both the colorimetric temperature measurement system and infrared thermometer are less than 1.2%, that can meet the requirements of the temperature measurement.