Abstract: To reduce the processing quality problems caused by mechanical structure vibration, an encoder vibration suppression algorithm was designed based on the principle of linear Kalman filtering and verified on the dual-servo-driven inner frame fixed-length conveying system in a YB416A hard packer. The algorithm iteratively calculates the current measurement values and predicted state values to find out the appropriate values as the true position values for the encoder, so that the interference values in measurements caused by mechanical vibration are filtered out to achieve mechanical vibration suppression function. The test results on YB416A hard packer in Wuhu Cigarette Factory showed that after Kalman filtering, the speed fluctuation of the main shaft encoder decreased from 1.65% to 0.83%, enabling the linear speed matching between the U-shaped knife roller and the spreading conveying roller to avoid inner frame double cut by the U-shaped knife. This method minimizes the instability of packer servo control system caused by mechanical vibration.