The invention relates to a finish grinding system for a cement roller press. The finish grinding system comprises an outer circulation vertical mill, a first elevator, a vibrating screen, a steady-flow bin, the roll press, a second elevator, a powder selecting assembly, a dust collector, a chute, a fan and a chimney, wherein a discharging port of the outer circulation vertical mill is connected with a feeding port of the first elevator, a discharging port of the first elevator is connected with a feeding port of the vibrating screen, a discharging port of the vibrating screen is connected witha feeding port of the steady-flow bin, a discharging port of the steady-flow bin is connected with a feeding port of the roller press, a discharging port of the roller press is connected with a feeding port of the second elevator, a discharging port of the second elevator is connected with a feeding port of the powder selecting assembly, a powder discharging port of the powder selecting assemblyis connected with the feeding port of the steady-flow bin. According to the finish grinding system, the feeding granularity is controlled, so that the roller gap fluctuation of the roller press is small, and thus the vibration strength of the roller press is greatly weakened, the cement performance is ensured, and meanwhile the cycle load and the energy consumption are reduced.