(1) the principle of quality concentration: the linear multilayer vibration sieve resulting from the structure is more complex and requires proper concentrated mass processing. For example, in the case of mass, the large vibrator stiffness can be regarded as an inelastic concentrated mass.(2) principle of stiffness concentration: linear vibration vibration multilayer vibration rigidity is large, quality is comparatively small, installation is not so concentrated, and there are many dispersion. When creating a mechanical model, this type of mass is not included in the model.(3) principle of damping concentration: damping of the system includes spring damping, damping of friction between components, damping between aggregate and sieve. These damping can be reduced to equivalent linear damping.