Modern various machine and equipment are more than on the gear reducer, generally USES bearing hole processing, and currently 1ta series boring coordinates are in single points, so in mass production to ensure its hole spacing tolerance, and low efficiency.A fine molding machine is a special machine, when using a series of molding method. Once processed clamping workpiece, hole spacing in design, and when the machine has two of the coaxial when spindle box, while processing by rail, which not only ensures the transmission distance between accuracy, but also guarantee the hole, and greatly improve the coaxial tolerance of machining efficiency. Can realize automation, production line. It meets the modern production accuracy and efficiency.This paper introduced a series of molding machine structure, working principle and control method, and automatic assembly line control principle and realization method.Keywords: a large series boring