Abstract: Based on the 0.04~0.07mm dissemination size of useful minerals, difficulty to achieve 90% monomer dissociation by the existing process and insufficient processing power，it was conducted to carry out the study of the fine grinding process of MiaoGou iron ore. It was finally determined to use a VTM - 1500 vertical grinding machine instead of the original two MQY2736 ball mill grinding as the third paragraph on the basis of the original first two paragraphs grinding process to improve 44.49% grinding fineness and monomer dissociation reach to 96.7% from 87.6%, which could indicates that the final iron concentrate grade was increased to over 66%from 65.2% with 30.2405 million yuan increasing economic benefit every year. At the same time, the vertical grinding machine could optimize process flow, solve the problem of large amount circulation, and increase 8.3 t/h of treatment capacity.