The utility model provides an upper roller device for calenders, improves the connection strength between the components of the upper roller by adopting key-connected torque transmission structure, and realizes the design purpose of eliminating the reduction in strength or even the component rupture caused replacement of all the forming rolls caused by the opening at the end part. The upper roller device mainly comprises a forming roll sleeve which is sleeved on a forming roll shaft; an axial water cavity used for cooling down the upper roller by a circulation flow is arranged in the forming roll shaft; ring-shaped limiting steps used for limiting the axial movement of the upper roller and a key slot are formed on the driving end of the forming roll shaft; a key used for transmitting torque to the forming roll shaft is mounted in the key slot; and the key connection adopted at the driving end of the forming roll sleeve transmits torque by the forming roll sleeve, and the limiting step adopted at the driving end of the forming roll sleeve is used for limiting the axial direction displacement of the forming roll sleeve during a rotation process. As the key is fixed in the key slot and a larger shear area is provided, the application requirement of transmitting larger torque is met.