Abstract: Ultra-low-grade copper polymetallic ore is an important component of domestic copper ore resources. This type of ore has a low storage grade and is difficult to recycle. Meanwhile, it requires higher processing index requirements and higher production costs. Aiming at the problem of insufficient operation rate of I-stage grinding classification system in 6000 t/d concentrator of an ultra-low grade copper polymetallic ore, the operation rate of I-stage grinding classification system was raised from 90.29% to 97.27% and increased by nearly 7 percentage points through systematic technological transformation, equipment technical transformation production precision management; The annual treatment capacity of the concentrator is increased by more than 150,000 tons, and the effective recovery of copper metal is 300 t/a, iron metal is 8500 t/a, molybdenum metal is 15 t/a, and the economic benefit is more than 25 million yuan/a. It achieves the aim of improving the technical index of grinding and increasing the efficiency of production.