A high-voltage large-section omega-shaped high-drop cable line adjustable positioning fixing fixture comprises a plurality of gantry frames on which a plurality of fixing brackets are detachably mounted; The fixing bracket comprises a mounting seat, a fixing lower clip body, an upper fixing clip body of the cable and a lower fixing clip body of the cable, and the fixing bracket is detachably mounted on the portal frame through the mounting seat and the fixing lower clip body; A low fixing clip body of that cable and an upper fixing clip body of the cable are arrange at the upper end of the mounting base, the upper surface of the lower fixing clip body of the cable and the low surface of the upper fixing clip body of the cable are semicircular matched with the cable, and the lower fixing clip body of the cable is connected with the upper fixing clip body of the cable to fix the cable; The invention can be flexibly combined under the high drop environment, and the installation position,the distance and the angle are determined according to the field high drop environment, thereby realizing the reliable fixation of the drop differences of different heights and satisfying the releaseof the thermo-mechanical stress.