A sliding device for a material shaft includes a shaft body, sliding units, spacers. An outer periphery of the shaft body has axial accommodating grooves. The sliding units and the spacers are spaced and arranged in the accommodating grooves. A top surface of each roller extends out of the outer periphery of the shaft body. When a material roll is sleeved on the shaft body, the inner wall of the material roll is in contact with the outer periphery of the rollers. When the material roll is to be mounted on or dismounted from the shaft body, the material roll is pushed in a direction so that the inner wall of the material roll rubs against the rollers, thereby rotating the rollers. The friction between the material roll and the shaft body is reduced for the material roll to be mounted on or dismounted from the shaft body effortlessly.