The invention discloses an image fusion method based on dynamic target detection, belonging to the technical field of image processing. The method comprises the following steps: detecting and extracting a moving object in an infrared image sequence; carrying out quick rectification on a low-light image by using the infrared image as a reference; then fusing infrared images and the low-light image; and finally, carrying out secondary fusion on the extracted object and the fusion image. Proved by experimental results, the fusion image obtained in the invention not only has the characteristic ofabundant information of an ordinary fusion method, but also has vivid infrared object indication characteristics. In addition, the invention can also provide coordinate information of the infrared object, which provides a probability for accurately positioning the object, and has wide application prospect in military and civil fields such as night investigation, security monitoring, and the like.