A multi-region performance analysis system for infrared detector based on QT/C++ is proposed to address the differences in the requirements for testing data analysis and screening among different types of infrared detectors. The analysis system is based on traditional infrared detector testing system, and performance analysis software is developed using QT software and C++ language. The developed software is embedded in the OpenCV plugin library and has functions such as region partitioning, blind element filtering, index calculation, and blind element cluster recognition. The test data from the very-long-wavelength 640×512 HgCdTe detector is used to verify the performance analysis function of the developed software. The verification results prove that the developed software has the ability to efficiently process data and accurately analyze performance, and can provide blind element positions and blind element cluster maps. Compared with existing testing systems, the proposed analysis system can improve performance analysis capabilities and testing efficiency for detectors of full array size and different materials.