In the field of space remote sensing, the long wave detector with wavelength of 10 μm or more is mainly based on HgCdTe photoconductive(PC) detector, which plays an important role in IR imaging. Nonuniformity is one of the outstanding problems in the long wave PC detector. A new type of long wave PC detector read-out integrated circuit(ROIC) in digital-analog mixed mode with nonuniformity correction was designed. The circuit could not only effectively solve nonuniformity of the linear long wave PC detector in resistance, but also increase the dynamic range of the output signal of the ROIC with almost no increase in power consumption. Simulation results show that the nonuniformity is greatly improved through the correction ROIC, which makes the nonuniformity reduce to less than 0.5%, and it can work at room temperature and low temperature. The correction circuit could not only solve the key problems in current project, but also have guiding significance for circuit future design of high performance large array IR detector.