In order to increase the angle of field and the detection distance, we designed an infrared imaging seeker using an 640×512 uncooled FPA. Firstly, we analyzed various structural types of infrared imaging seeker. Based on the characteristics of the design requirements, the universal support type structural type is selected. Secondly, we optimized the image quality of the infrared seeker optical system and analyzed the satisfaction of the frame angle and blind area. Finally, the test results of the real prototype show that the infrared imaging seeker has good imaging quality and can meet the requirements of searching and tracking targets.