Abstract: Described here in the paper is an automatic steel pipe weighing & length-measuring system,involving such aspects as the operation principle,the system configuration,the software design and innovative hi-lights of the system design,etc.The system is controlled by S7-200 SMART PLC and has the WinCC configuration HMI,having realized the connection between the PLC and the weighing instruments.Moreover steel pipe weighing and length-measurement are completed on one operation station and at the same time,which greatly shortens the inspection time,and gets the errors caused by manual measurement as made with the measuring reel.The actual application result shows that the said system features consistent performance,complete functions,and easy operation,having been satisfactory to the need by the production site.