To solve the dynamic range limitation of an Uncooled Infrared Focal Plane Array (UIRFPA) for imaging multiple targets, a method which can adjust dynamic range according to the target is proposed on the basis of the characteristics of the detector. Before integration, the capacitance is adjusted in real time according to the grayscale distribution of the selected target in an initial image. At the same time, the pixel bias is configured point by point to adapt the dynamic range and Non-Uniformity Correction (NUC) is conducted. Then, the best imaging effect of the locality of the target is achieved successively. Finally, an infrared imaging system for verifying the feasibility of the method is built. The results show that the proposed method can realize the real-time adjustment of dynamic range and obtain clear local key target images. Because the problem of mismatch between dynamic range and target is solved, it is of great significance to the application of uncooled infrared imaging system in multi-target scenario.