The solar irradiance absolute radiometer (SIAR) adopts the thermopile-type detector to convert incident solar light power into electrical power, achieving the measurement of total solar irradiance. However, the thermopile detector has the following limitations. Firstly, it is difficult to further improve the sensitivity due to the limitation of the number of thermocouples. Secondly, the consistency of the main and backup chambers is difficult to be ensured due to the limitation of the complex fabrication process. To solve these problems, this paper develops a thermoelectric bridge absolute radiometer with high-sensitivity and high-precision based on the high interchangeability and high-resolution characteristics of the Wheatstone bridge, and adopts a new detector cone cavity structure and a new thermal connection method. The test results show that the time constant of the detector is 9.69 s, the sensitivity is 0.078 W/m², and the measurement repeatability of tungsten light source is better than 0.07%, which can meet the observation requirements of total solar irradiance with a precision of 0.1%.