There are some problems in HRM3400B raw meal vertical grinding system of a 5 000t/d cement clinker production line, such as high power consumption, high resistance, low operation efficiency, high comprehensive moisture content of grinding materials, many air leakage points of the system, large air leakage and so on. And then it are upgraded by optimizing the structure of cyclone inlet, heightening the inlet and upper shell of whirlwind cylinder, lengthening the inner cylinder of whirlwind cylinder, adding hot air pipe, increasing the angle of grinding sliver, adding buffer box at the end of slag discharge belt conveyor, replacing the grinding roller seal cover with a new type of internal labyrinth seal cover, removing the lower pressure reamer of cyclone tube and replacing it with unpowered flip plate valve, replacing all the dust collector cylinders with stainless steel materials, etc. After revamping, the pressure difference of raw meal vertical grinding machine is reduced by 183Pa, the oxygen content of waste gas at the end of online kiln is reduced by 1.8% and 2.0%, and the power consumption of mill is reduced from 16.33kW.h/t to 13.70kW.h/t. The production cost is effectively reduced and the transformation effect is remarkable.