In order to find out an automatic monitoring method of plant insect pests, non-destructive detection software system with compatibility of PC hardware, Windows XP and Windows 2000 software environment was developed based on the information fusion of image and spectrum, which was programmed by VC++ and Matlab language. Working principal and process of the system, hardware composition and software system were introduced. The system could collect image and spectral data automatically, process data, predict the damaged degrees (DD) and display the detection results. Finally, the system was used to detect the DD of leaves. The detection results from the experiment showed that the proposed system could be used for non-invasive detection of DD of leaves with high accuracy and reliability．