A yarn making method includes a raw-material yarn; first rollers pulling the raw-material yarn; an entangling point generator subjecting the yarn to jet-forming of entangling points; a cleansing chamber cleansing the yarn that has generated the entangling points; a material chamber provided with a graphene-containing attachment material to be attached to the yarn that has generated the entangling points and has been cleansed; second rollers pulling the yarn that has past the entangling point generator, the cleansing chamber, and the material chamber; a heating chamber having the attachment material secured to the yarn by means of heat-setting; third rollers controlling a heating time of the yarn in the heating chamber; and fourth rollers winding and shaping the processing-completed yarn so as to have the graphene-containing attachment material long preserved in clothing.