According to paper tension control requirements of paper machine, based on the Siemens PCS7 platform, and using S7-400H PLC as the control center, a tension control system was designed through the OPC technology. The tension set value in WinCC was regulated optimatically using linear programming function of Excel. The main composition and working principle of the system was introduced. The design of system's hardware and software for each function was discussed. The control flow of main program was given for system components. The actual operation showed that the paper tension control system can realize optimal tension control; it has the advantage of easy realization and strong self-regulation ability; it obviously reduces the occurrence of paper breaks and folds.