To address the issue of performance degradation in infrared detectors caused by high-energy particle irradiation in space applications, this study investigates the effects of displacement damage on key parameters of HgCdTe infrared focal plane arrays through proton irradiation experiments. By comparing the performance of the focal plane before and after irradiation and applying semiconductor radiation effect theory, the mechanisms by which displacement damage affects the characteristics of HgCdTe infrared focal planes are analyzed. The results indicate that proton irradiation leads to increased dark current, noise, and number of blind elements, with the extent of degradation proportional to the radiation fluence. These findings offer a helpful reference for future research on the radiation effects in HgCdTe infrared detectors.