Infrared　image　processing　is　a　conventional　topic,　but　the　hardware　design　and　implementation　for　infrared　image　processing　algorithms　are　full　of　challanges,　especially　for　special　purpose　infrared　detectors　which　have　customized　interfaces　and　protocols.　Moreover,　some　customized　infrared　detectors　only　generate　the　infrared　image　with　very　poor　quality.　Therefore,　in　this　paper,　we　design　and　implement　an　infrared　image　preprocessing　system　based　on　FPGA　for　customized　infrared　detectors.　We　propose　a　hardware　architecture　that　includes　the　whole　process　from　the　input　of　detector,　image　processing,　to　final　infrared　video　stream　output　and　display.　Our　hardware　architecture　is　able　to　adapt　to　different　customized　infrared　detectors,　which　has　the　characteristics　of　real-time,　low-power,　dynamic　parameter　configuration,　high　processing　efficiency　and　stable　imaging　effect.　We　have　implemented　it　on　Xilinx　FPGA.　The　infrared　imaging　effect　is　significantly　improved　with　limited　FPGA　resources　(about　only　1.6M　LUT,　420　BRAM　for　all　algorithm　models　on　Xilinx　zc706　evaluation　board),　the　image　processing　speed　can　reach　to　225Hz　with　the　resolution　of　320*256.　Our　preprocessing　system　can　generate　real-time　video　for　display　with　1920*1080@60Hz.　©　2021　IEEE