The invention discloses a gap adjusting device, a gap adjusting method and transmission equipment. The gap adjusting device is used for adjusting a gap between two rollers which are oppositely arranged, at least one of the two rollers can move up and down relative to the other roller, the gap adjusting device comprises a driver and a controller, the driver is used for driving the movable roller to move up and down, the controller is internally provided with a preset gap scope, and the controller is connected with the driver and is used for controlling the driver to drive the movable roller to move up and down so as to make the gap between the two rollers be in the preset gap scope. According to the gap adjusting device, the rollers are driven by the driver to move, the driver is controlled by the controller to do motion, so automatic adjustment on the gap of the two rollers can be realized, and manpower cost is reduced. The device further employs a displacement measurer and a piezoelectric inductor, gap adjusting precision is improved, and product damage risk is reduced.