The present invention belongs to the field of automobile performance detection equipment, and is especially one kind of precisely subdivided flywheel set system of automobile chassis roll test bed. The test bed flywheel set system consists of a main shaft, a clutch unit, a bearing seat unit, a flywheel unit, a shaft coupling and a frame unit. It features the main shaft mounted through the bearing seat unit on the frame unit; the flywheel unit comprising several flywheels of different rotation inertias, mounted on the main shaft and connected separately with corresponding clutches; the shaft coupling mounted on one end of the main shaft and connected to the power source; and the flywheel set in the system in binary dividing method.