Infrared earth sensors are an important attitude measurement component of satellite control subsystems. They provide the information about the satellite’s attitude relative to the pitch and roll direction of the earth radiation disk. The infrared detector is the key part of such a sensor. In this paper, we discuss research on micro-infrared thermopile detectors for space applications. Infrared thermopile technology and the technical index of the detector are introduced. The ring effect, temperature compensation, response compensation, nonuniformity correction, and blind element processing of the detector are studied. The scheme design and field programmable gate array (FPGA) design of an infrared earth sensor image processing system are described. Test results show that system’s attitude measurement deviation is less than 0.2°. Thus, FPGA-based micro-infrared thermopile detectors based on FPGA can be used for attitude measurement in low earth orbit satellites. Offering miniaturization, low power consumption, and low cost, this technology has the potential to replace traditional mechanical scanning infrared earth sensors and has broad application prospects.