Nowadays, the complexity of image processing algorithm is more and more high, the amount of data in image processing is more and more large, and the real-time performance of image processing is very important. In order to solve the problems of im- age preprocessing and real-time video stream data, this paper presents a method of image acquisition and processing system based on FPGA and OV5640 using Sobel operator for edge detection. FPGA transmits the video stream data collected by OV5640 camera to SDRAM, which is processed by Sobel operator template and then is displayed through VGA. The design is based on EP4CE10F17C8, which is the FPGA chip of the Cyclone IV series of Intel company. The experimental results show that the real- time processing of video stream data can be realized by using pipeline design and ping-pong operation based on FPGA and Sobel edge detection algorithm.