The invention discloses a horizontal movement mechanism for storage boxes, and belongs to the field of packaging and conveying mechanical equipment. The horizontal movement mechanism comprises a conveying support, a fixing support, a horizontal movement plate and horizontal movement driving mechanisms. The conveying support is horizontally provided with a horizontal movement groove. Multiple box push plates matched with the horizontal movement groove in width are evenly and vertically arranged on the upper side of the horizontal movement plate. The horizontal movement driving mechanisms are arranged on the two sides below the horizontal movement plate correspondingly. Each horizontal movement driving mechanism comprises a horizontal movement motor, a rotary support, a fixed support, a horizontal movement support and a horizontal movement connection plate, wherein the upper end of the rotary support is provided with a rotary plate, a supporting plate is hinged to the upper end of the fixed support, one end of the horizontal movement connection plate is hinged to one end of the supporting plate, the other end of the horizontal movement connection plate is hinged to one end of the rotary plate, and a fixed connection plate is arranged in the middle of the upper side of the horizontal movement connection plate. According to the horizontal movement mechanism, structural design is reasonable, the storage boxes can be rapidly, efficiently, stably and accurately subjected to horizontal movement and conveying, machining efficiency and quality of the storage boxes are improved, and requirements for production practicability are met.