Traditional laser power meter has the defects of large volume, slow response, and are difficult to guarantee the detection accuracy, so a laser power measurement method based on high performance black silicon MEMS thermopile power meter is put forward. The test method uses the laser thermal effects, and CO2 laser is used as the measured laser source, and the black silicon MEMS thermopile detector is the laser detection sensor. Based on the principle of energy conversion, the absorbed laser radiation by a thermopile is converted into its thermodynamic energy, and the thermodynamic energy is input to the CMOS interface circuit in the manifestation of the potential. Potential input data are collected and processed by TopView2000 application software, and the data of the laser power are obtained. Under the room temperature condition, the MEMS laser power detection system repeat test is carried out under the CO2 laser irradiation with different duty cycles and different light time. Under the conditions of 30% laser output duty ratio and the 150 ms total light time, the experimental results show that the response time of the system is 14.92 ms, the laser power value is calculated as 23.01 W, and the measurement uncertainty of the system is 0.55%, which meets the needs of high precision, low cost, low power consumption and portability of laser power in practical application.