To address the issues of low operating current and operating efficiency long term less than 55% of the rated power in the roller press pre-grinding system, systematic optimization and transformation were implemented. The structure of the feeding device above the weighing bin was modified by adjusting the feeding point and adding bidirectional regulating valves, which solved the problems of uneven longitudinal distribution and horizontal segregation of materials from different sources in the bin, stabilized the feeding pressure of the roller press and effectively corrected deviation. Meanwhile, a multi-channel distributing device based on the principle of "reservoir spillway" was innovatively designed and installed at the inlet of the V-type separator, significantly improving the dispersion uniformity of materials, forming a stable and continuous material curtain, enhancing the separation efficiency and reducing the circulation of fine powder. After the transformation, the operating current of the roller press increased stably from 35A to 45A, the roller gap deviation decreased from 16mm to within 3mm, and the system operating pressure reached the set value. The system output increased by 10t/h, the power consumption per ton of cement grinding decreased by 2kW·h/t, and the specific surface area and early strength of the cement product were improved. Calculated based on annual operating time, the annual electricity cost saving is about 740 000 CNY, showing significant economic benefits. This practice indicates that optimizing feeding uniformity and improving separation efficiency are key to fully utilizing the efficiency of the roller press pre-grinding system and achieving energy saving and conservation in the grinding system.