A glass screen film applicator, comprising: a carrier including a mounting slot and an accommodating trough, wherein the carrier defines a longitudinal direction and a width direction perpendicular to the longitudinal direction, and the accommodating trough includes a rail hole recessed in a bottom thereof and parallel to the longitudinal direction; a positioning member integrally formed as a one-piece structure and mounted in the mounting slot, wherein the positioning member includes an L-shaped structure and a plurality of positioning pillars extending from the L-shaped structure and arranged in a row parallel to the longitudinal direction, the L-shaped structure has a positioning corner arranged on an inner side of the L-shaped structure, each of the positioning pillars is perpendicular to the longitudinal direction and the width direction, and the positioning corner has two lateral walls (2111, 2112) respectively parallel to the longitudinal direction and the width direction; and a clamping mechanism including a holder and a moving unit, wherein a part of the moving unit is arranged in the carrier, and the other part of the moving unit passes through the rail hole and is connected to the holder, wherein the moving unit is configured to move the holder for adjusting a relative position between the holder and the positioning corner, and the positioning pillars are configured for positioning a glass screen film structure; and wherein when a mobile device is disposed on the carrier, the holder and the positioning corner are configured to respectively clamp two diagonal corners of the mobile device by the moving unit, and the positioning pillars are configured to allow the glass screen film structure to be disposed on and aligned with the mobile device. a carrier including a mounting slot and an accommodating trough, wherein the carrier defines a longitudinal direction and a width direction perpendicular to the longitudinal direction, and the accommodating trough includes a rail hole recessed in a bottom thereof and parallel to the longitudinal direction; a positioning member integrally formed as a one-piece structure and mounted in the mounting slot, wherein the positioning member includes an L-shaped structure and a plurality of positioning pillars extending from the L-shaped structure and arranged in a row parallel to the longitudinal direction, the L-shaped structure has a positioning corner arranged on an inner side of the L-shaped structure, each of the positioning pillars is perpendicular to the longitudinal direction and the width direction, and the positioning corner has two lateral walls (2111, 2112) respectively parallel to the longitudinal direction and the width direction; and a clamping mechanism including a holder and a moving unit, wherein a part of the moving unit is arranged in the carrier, and the other part of the moving unit passes through the rail hole and is connected to the holder, wherein the moving unit is configured to move the holder for adjusting a relative position between the holder and the positioning corner, and the positioning pillars are configured for positioning a glass screen film structure; and wherein when a mobile device is disposed on the carrier, the holder and the positioning corner are configured to respectively clamp two diagonal corners of the mobile device by the moving unit, and the positioning pillars are configured to allow the glass screen film structure to be disposed on and aligned with the mobile device.