The invention discloses an automatic system for loading and unloading. The automatic system for loading and unloading comprises a storage yard transporter, a transition yard transporter and a moving chain, wherein the storage yard transporter comprises a standing seat, a big arm, a small arm and a vacuum sucker, the big arm is connected with the standing seat, and the small arm is connected with the vacuum sucker and the big arm; the transition yard transporter comprises a mounting seat, a vertical moving seat, a cylinder, a sucker, a guide rail, a sliding block and a mounting plate, the mounting seat is arranged beside the moving chain, the vertical moving seat moves vertically on the mounting seat, the vertical moving seat is provided with the cylinder arranged in a position close to the mounting seat, the guide rail is mounted on the vertical moving seat, the sliding block moves on the guide rail, the cylinder is connected with a side surface of the sliding block, the mounting plate is mounted at the upper end of the sliding block, and the sucker is mounted at the tail end of the mounting plate; and the moving chain comprises a moving tank, and rollers placed evenly are arranged on the moving tank. According to the automatic system provided by the invention, the transition yard transporter can stack goods into vehicles accurately, or transport the goods out of the vehicles accurately through automatic control according to positions and dimensions of the vehicles, and automatic loading and unloading as well as stacking are realized.