Ground particle size is an important index parameter in the feed production process, which affects the nutritional value of feed, animal digestion and absorption, grinding cost, subsequent processing and product quality.Screen is the main accessories to control the particle size of the comminuted products, and also one of the main vulnerable parts of the feed hammer mill.At present, screen damage phenomenon is very common in feed production, affecting the quality of feed products processing,feed enterprises often through manual detection screen damage, there are many problems in the actual production process.This study designed a convenient and fast online screen breaking detector to realize the rapid identification and monitoring of screen breaking, aiming to provide a new idea and method for screen breaking identification of hammer mill in the course of feed crushing.