The invention discloses an automatic container loading method used for a steel structure workshop. The method comprises the following steps that (a) hydraulic equipment is mounted; (b) a jig frame is hoisted, and equipment on a jig frame is connected; (c) steel components and a bracket are packed and put on the jig frame; (d) the bracket is separated from a subgrade box; (e) the jig frame is pulled into a container; (f) the jig frame is pulled out of the container; and (g) box iron rails in the container are pulled out, and then the container is hoisted to an automobile to be carried away through a crane. According to the automatic container loading method, traditional semi-mechanization is changed into existing mechanization, the mechanization degree is high, through the change, the working efficiency is improved, the product capacity is increased, meanwhile, the labor force input is reduced, and original manual operation of laborers is changed into button control operation; and due to the change of the operation mode, lots of the carrying, loading and unloading time of logistics/transportation cost is reduced, and thus the logistics/transportation cost is reduced.