In order to improve the imaging quality and real-time demands of infrared foccal plane (IRFPA) detectors, an infrared image digital processing system with a high speed signal processer in its centre was proposed. The composition of the dual infrared imaging system, the hardware structure, the chip selection, data processing, as well as the principle of infrared image display and the processing of the video synthesis were described; At the same time, the verilog codes of the display chip ADV7123 were given. The results of imaging were certified satisfactory, which can meet the infrared image real-time demands and has high value in applications.