A cheek plate device is provided for a stuffer box crimper, which has brackets, adjusting mechanisms, cheek plates, a base frame and a pair of nip rollers. The adjusting mechanisms are mounted on the brackets, which can slide relative to the bracket. The cheek plates are mounted on the inside of the adjusting mechanisms. Two identical brackets, adjusting mechanisms and cheek plates are mounted symmetrically at two sides of the pair of nip rollers and affixed on the base frame. The cheek plate device further comprises fluid thrust devices, which include fluid inlets and cylinders located on the brackets. One end of the adjusting mechanism is inserted into and coupled with the cylinder. The fluid of the thrust device flows into the cylinders through the inlets and pushes, via the adjusting mechanisms, the cheek plates toward the sides of the nip rollers. The thrust device can work hydraulically or pneumatically.