The method for heating a screw cylinder of a spinning machine, designed by the invention, specifically comprises that: for the screws equal to [phi]105 millimeters and below [phi]105 millimeters, electromagnetic heating is implemented in each heating region by using 220V power source; three-phase four-wire 380V power source is utilized to power apparatus above [phi]105 millimeters, and 2-4 electromagnetic heating coils are utilized to heat in each hearing region; an electromagnetic controller rectifies alternating current to direct current and converts the direct current into high-frequency current having frequency of 20-40kHz; when magnetic lines of force pass through the screw cylinder of a magnetically conductive metal material, numberless small vortexes are generated in the metal so that material in the screw cylinder reaches ideal heating effect. The screw cylinder device resulted from the invention makes use of electromagnetic induction principle to heat the screw cylinder and is provided with a heat preservation layer, a heat insulation layer and the like outside of the screw cylinder, thus solving the problem that heat is dispersed to air to maximize heat efficiency.