Aiming at the target detection of video stream images,a real-time multi-motion target detection algorithm is proposed based on the theory of inter-frame difference.According to the application of video images in real-time processing,based on the characteristics of parallel processing of FPGA hardware platform,the algorithm is implemented in FPGA hardware,verified by MATLAB environmental algorithm,and implemented in the designed FPGA video image processing system.The system is mainly composed of four parts:image acquisition module,image cache module,image processing module and image display module.The image data is collected through OV5640,and then the data is processed by a series of algorithms such as difference,filtering and morphology,and is stored in DDR3,finally is displayed by VGA.The experiment results show that the system can stably track moving targets within a certain ranging range,can display in real time,has a high multi-target detection and recognition rate,and can detect multi-motion targets in video stream images in real time.