With the modularization method and utilizes characteristic of parallelity and pipeline of FPGA, interval dot difference with adaptive threshold segmentation algorithm is designed and imp lemented. The imp lementation consists of two modules: interval difference algorithm module and adap tive threshold algorithm module. The former carries out pipeline computation of interposing gradientwith synchronizing time sequence and clock; the latter conducts adaptive adjustment of segmentation thresholds in real time with the change of image background according to statistic characteristic of background. Results of simulation and experiments show that this design can process image segmentation with short delay and satisfy the real-time processing requirement.