Complete set of continuous rolling mill equipment production line is a longitudinal rolling mill unit. The continuous 3-roll hydraulic press roll stands are adopted as the mainstream model, equipped with the mandrel circulating and retaining system, producing precision steel pipes efficiently and with high quality, suitable for steel pipe production with large scale and high precision, which is the highest level of pipe mill nowadays. The mill unit is composed of piercing mill, continuous pipe rolling mill, extractor, stretch reducing mill and other main deformation units. Its products are mainly used for oil pipe, pipeline, structural tube, fluid tube, boiler tube and so on.