Package sealing method and controller

The invention discloses a package sealing method and a controller, more than two servo motors are connected with the controller, the servo motors are connected with a sealing module, the controller controls movement of the servo motors, opening and closing of the sealing module are achieved through movement of the servo motors, package sealing is achieved through closing of the sealing module, and the method is applied to the controller. An electronic cam coupling relation between a servo shaft of each servo motor and a virtual main shaft of the controller is established, and the electronic cam coupling relation is used for controlling synchronous movement among the servo motors through the change of the virtual main shaft, so that position, speed and torque differences of the servo motors caused by differences of scanning periods do not exist; determining whether the position of the virtual spindle exceeds a threshold value in real time; if yes, the servo motor is controlled to drive in a low-current mode, s