GIS is a powerful tool on the study of crop diseases and pests occurrence and development, and plays an important role in the aspects of diseases and pests dynamic forecasting, diagnosis, visual simulation, evaluation of control strategy and integrated management. Potato late blight is the biggest thread in potato production, according to the rule of occurrence, popular and control of potato late blight, as well as the spatial characteristics when it occurred, visualization simulation method and technical ideas based on GIS was discussed in the process of potato late blight occurrence, and the influence of simulation results to control strategy was illustrated in the paper.