Abstract: Identification of plant diseases and insect pests was basis for plant protection and utilization.With development of computer image recognition technology，the use of computer image processing technology to obtain plant diseases and insect pests information could greatly improve efficiency of plant disease identification.SVM toolbox and Matlab′s graphical user interface toolbox GUI were designed and developed for identification system of alfalfa plant diseases and insect pests，and image database under natural environment and specific environmental image database were constructed，which laied foundation for development of plant pests and diseases image recognition technology in the future.