Cabbage leaves are consumed as a healthy vegetable but the plant is very susceptible to attack by leaf caterpillars (P. xylostella). The residue from the periodic use of insecticides is very dangerous to human health. Hence Decision Support System (DSS) was developed which can be used as a reference when spraying insecticides is carried out. The system is intended to estimate the cabbage leaf damage based on web-based photo imagery that is used for detecting the percentage of pest attacks so that pesticides are only applied if the damage to the cabbage leaves is detected to be rather severe. Users are required to upload photos of cabbage plants to be detected. This research is carried out through literature studies, theoretical studies, data collection and location surveys of cabbage plant centers, statistical modeling, making a cabbage leaf hole display detection system with photo images, and making packages or libraries for models that have been developed, adding features that make it easier for users to run it. This developed system after passing the development process carries out 100% black box testing works according to the desired requirements. The implementation of pest experts and testing of this system gets an accuracy of about 87%, so the implementation is carried out on users. This developed system after going through the development process is carried out 100% blackbox testing to function according to the desired needs. The implementation of pest experts and testing of this system gets an accuracy of about 87%, so the implementation is carried out by the user. The results of this study have an analysis that can be stored in a database so that the utilization of recording analysis results can be directly stored in the database, can be printed, and can issue results from the Decision Support System for spraying cabbage pests.