A device for quick splicing of a display screen is provided, the device comprises a left assembly (2) and a right assembly (3). The left assembly (2) comprises a rotation fixing seat (22), a rotation angle seat (20), a rotation locking mechanism, and a step angle-adjusting and clamping mechanism; the rotation angle seat (20) can lock with the right assembly (3), and is rotatably connected to the rotation fixing seat (22); the rotation locking mechanism is disposed between the rotation fixing seat (22) and the rotation angle seat (20); when the rotation locking mechanism is unlocked, the rotation angle seat (20) can rotate relative to the rotation fixing seat (22); and when the rotation locking mechanism is locked, the rotation angle seat (20) is fixedly connected to the rotation fixing seat (22); the step angle-adjusting and clamping mechanism is disposed between the rotation angle seat (20) and the rotation fixing seat (22). Owing to the step angle-adjusting and clamping mechanism, the splicing device can realize the step adjustment of a splicing angle, and can preinform an operator of the angle value to be spliced, thus facilitating splicing.