The invention provides a glass cutting device. The glass cutting device comprises a stander, a plurality of suction discs, two cutting mechanisms, a correction mechanism, a side separating mechanism and a fastening bolt, wherein the suction discs are fixedly mounted on the stander, the two cutting mechanisms are oppositely mounted at the upper and lower ends of the stander, the correction mechanism comprises an L-shaped guiding slot and a driving mechanism, the L-shaped guiding slot is fixedly formed in the stander, the driving mechanism is movably mounted in the L-shaped guiding slot, and theside separating mechanism is movably mounted on the stander. The two surfaces of glass are cut by virtue of oppositely mounted cutting mechanisms, so that the relatively cutting effect is achieved when relatively thick glass is cut; the position of the glass is corrected by virtue of the correction mechanism, so that the complex manual correction process is avoided; and the cut glass is processedby virtue of the side separating mechanism, so that the cut glass is completely separated from a master batch and does not need to be manually processed in the subsequent process.