Compared with the monochromatic detector, the two-color detector has higher detection accuracy and is the typical representative of third-generation infrared detectors. Type-II superlattice has outstanding advantages such as wide absorption spectrum and high uniformity, and can be used to prepare two-color detectors. Annealing technology can improve the performance of two-color type-II superlattice devices by improving the quality of sidewall passivation and the quality of contact between materials and electrodes. By conducting a series of annealing experiments at different temperatures on the device, the effect of annealing on the performance of mid-/long-wavelength two-color type-II superlattice infrared focal plane devices is analyzed and studied. By optimizing the annealing process, the long-wavelength corresponding impedance of the pnp structure device can be increased by 4.6 times, and the long-wavelength corresponding impedance of the npn structure device can be increased by 31%. Compared with improving device performance by optimizing material structure and device structure, annealing has outstanding advantages such as high efficiency and simplicity. This study has certain reference significance for the performance improvement of mid-/long-wavelength two-color type-II superlattice infrared focal plane devices.