The invention discloses a device for repairing vertical concrete cracks by using a high-ductility cement-based material. The device comprises a fixation device and a template assembly. According to different crack generation positions and directions, movement is done conveniently and mounting or dismounting can be carried out simply. Besides, the invention also discloses a method for using the device. Repairing zones including weak bonding segments and bonding segments are arranged at the two sides of a to-be-repaired crack; and then crack repairing is carried out by using the device. The device is convenient to mount or dismount; and with the high flexibility of the high-ductility cement-based material, the flexibility of the repairing zone is enhanced and thus the crack repairing weak zone can be enhanced.