Aiming at the problems of low resolution, narrow field of view and non-uniformity of traditional infrared array detector, a scanning imaging method based on infrared point detector was proposed. Firstly, a scanning mirror driven by a micro motor was used to obtain the infrared hot spots on the surface of the object, which were converged to the infrared point detector through the optical lens. Then the signal processing board collected and processed them to generate infrared grayscale image. Finally, a multi threshold segmentation pseudo-color mapping model was used to transform grayscale image into pseudo-color image. The experimental results show that the infrared point detector scanning imaging method can realize the large field of view and high-resolution imaging of the infrared scene, and the point detector has the advantages of simple manufacturing process and low cost. It effectively breaks the limitations of technical and cost constraints of the large planar array detector in the traditional high-resolution imaging system, and is more conducive to the promotion and application of the infrared imaging technology.