The invention discloses a horizontal moving device of a yarn holder crossbeam. The horizontal moving device comprises a yarn holder, a yarn holder crossbeam, a yarn holder crossbeam support rack, a slider, a linear guide rail, a front support, a rear support, a servo motor, a ball screw pair, a cushion, a spacer bush, a matched pair angular contact ball bearing, a sleeve, a flange plate, a locking nut, a diaphragm coupler and a limit block and is characterized in that the servo motor is used to directly drive the ball screw pair to rotate and transmit power to the ball screw pair, and the power is transmitted to the yarn holder crossbeam through the front support on the ball screw pair so as to allow the yarn holder crossbeam to move axially. The horizontal moving device has the advantages that the movements of a spinning frame are reduced, a doffing device structure is simplified, accuracy is increased, the space occupation of the outward swinging action of the yarn holder is reduced, doffing time is reduced, and production efficiency is increased.