Abstract: An assembly device for assembling a screw into a locking hole of a circuit board includes an assembled board and a guiding sleeve. The assembled board is configured to press against a circuit board. The guiding sleeve is movably arranged in the assembled board. A vertical channel is formed in an interior of the guiding sleeve. When the assembled board presses against the circuit board, one end of the guiding sleeve abuts against the circuit board, and the vertical channel is opposite to the screw hole on the circuit board. The screw is accurately assembled into the screw hole of the circuit board, thereby improving assembly efficiency.