System composition and operation principles of the drive circuit of an infrared focal plane array (IR.FPA) detector are introduced. Single field-programmable gate array (FPGA) chip is used to control the detector and pre-process infrared images so as to reduce the design size of the whole system and increase design integrated level.The algorithm implementation of FPGA is introduced in detail. The design method and process of key module aregiven. The feasibility of the method is verified with a detector of 640×512 IRFPA. The images are clear with highcontrast and the image post processing requirements are met.