Considering the limitations of thermoelectric generators, the integration of thermoelectric generator with two-dimensional fan-shaped thermal metamaterial energy harvesting device is proposed to improve the thermal-to-electrical energy conversion efficiency of thermoelectric generator (TEG) by regulating the thermal field. Based on the COMSOL Multiphysics software simulation, the influences of different materials on the performances of energy harvesting devices in thermal field regulation are investigated. The performances of the selected materials are simulated , indicating that the energy harvesting device can effectively regulate heat flow, the temperature gradient in the center of it is increased by eight times compared with the natural material under the same simulation conditions. The generated electrical energy of thermoelectric generators of different sizes is studied, then three-dimensional modeling and processing of the energy harvesting device are completed by carefully considering the processing accuracy and testing difficulty. The experimental test system is set up to observe the temperature distribution of the energy harvesting device equipped with an infrared thermal imager, The test results demonstrate that the energy harvesting device can effectively regulate the thermal field. In comparison with the natural material, the working efficiency of the thermoelectric generators can be increased by 3.2 times under the same experimental condition, which has specific practical significance for promoting the rapid development of thermoelectric power generation technology.