Automated guided vehicle (AGV) is used widely in many industrial applications to transport materials. A long-travel material transport system is designed and controlled in this paper for a unit load AGV to transfer the material pallet from AGV to the load stand and back, including a both-side three-level push-pull load-transfer mechanism and a programmable logic controller (PLC). AGV follows the path of the magnetic tapes in the floor, and locates itself according to the RFID tags beside the load stand. The PLC detects the docking position of AGV and the load stand, and controls the horizontal and vertical movement of the load-transfer mechanism by using a stepper motor and an electric push rod. The load transfer experiments of our AGV testify the performance of this material transport system.