In the original first and second series of fine screen and regrinding process of Liaoning Shougang Iron Boron Co., Ltd.concentrator, the screening operation is a combination of "pre-inspection and inspection screening", and the total screening quality efficiency is only 27.18%.In order to reduce the cycle of screening equipment load and reduce the overgrinding phenomenon of a large number of fine particles in the second-stage grinding.The concentrator has reformed the screening process of the second series of fine screen and regrinding on site.The pre-screening and inspection screening are separated.The original Lukai high frequency fine screen is still used for pre-screening, and the Derek high frequency fine screen with a vibration force of 7.3 G is used for inspection and screening.After the transformation is completed, the screening quality efficiency, sieved products particle size and TFe grade of the second series are examined and compared with the first series.The results show that through the process transformation, the total screening quality efficiency of the second series is 38.29%, which is 11.11% higher than that of the first series, the final screening product content of-0.074 mm is increased by 5.29%, and the TFe grade is increased from 44.81% to 46.75%, the processing capacity of raw ore is increased by 1.87 t/h.After the pre-screening and inspection screening are separated, the total screening quality efficiency, the production efficiency of the concentrator and the TFe grade of the concentrate have been improved.The concentrator increases economic benefits by about 7.52 million yuan per year, which can provide a reference for the optimization of the fine process optimization of other similar processing plants.