A glass screen film applicator includes a carrier, a positioning member integrally formed as a one-piece structure, and a clamping mechanism fastened to the carrier. The carrier includes a mounting slot and an accommodating trough, and the accommodating trough includes a rail hole recessed in a bottom thereof. The positioning member includes an L-shaped structure and a plurality of positioning pillars extending from the L-shaped structure, and the L-shaped structure has a positioning corner arranged on an inner side thereof. The clamping mechanism includes a holder and a moving unit. The holder and the positioning corner respectively clamp two diagonal corners of a mobile device by the moving unit, and the positioning pillars allow the glass screen film structure to be disposed on and aligned with the mobile device.