Abstract: A method for treating the surface of a titanium alloy comprising a pretreatment process for cleaning a workpiece to be treated comprising a titanium alloy with an acid, a heating process for heating the pretreated workpiece in an oxidative atmosphere for a predetermined period of time to form a composite layer comprising oxide layers and oxygen-enriched layers on the surface of the workpiece, and a descaling process for rapidly quenching the treated workpiece to remove a scale layer formed as an outermost layer of the composite layer on the surface of the workpiece; or, without the pretreatment process, comprising the heating process, the descaling process, and an aging process for aging by maintaining the workpiece at a predetermined temperature; or, comprising the pretreatment process, the heating process, the descaling process, and the aging process, thereby adequately improving the abrasion resistance and burning resistance of the workpiece and preventing an increase in abrasion of a partner part sliding