Abstract: To address the need to test the output power of ultraviolet, visible, and infrared lasers, this study proposes a thermopile laser power meter composed of a heat transfer body, an absorption layer, an insulating layer, and a thermocouple. Combining the thermal effect and Seebeck effect theory, Solidworks 3D design software is used to build models of different key structure sizes, and a thermoelectric coupling simulation analysis model is established using ANSYS Workbench simulation software to analyze the influence of key structure size parameters on the output voltage and temperature distribution. The thermopile laser power meter is designed using mechanical processing, coating, and sandblasting, and the package structure and circuit compensation are designed to amplify and calibrate the output voltage. The results show that the key factors affecting the output voltage of the laser power meter are the thickness of the heat transfer body, the number of thermal couples, and the length of the thermal couple.