The　simulation,　verification　and　realization　of　complex　control　arithmetic　are　introduced　in　detail.　A　compound　Fuzzy　PID　level　control　system　is　realized　on　Siemens　PROFINET　platform.　The　communication　method　between　supervision　configuration　software　WinCC　6.0　and　engineering　calculating　software　MATLAB　through　OPC　technology　is　introduced　in　this　paper.　Hardware　configuration　and　programming　are　completed　by　STEP7　provided　by　Siemens.　Compound　Fuzzy　PID　arithmetic　is　realized　by　MATLAB.　The　programming　and　calculating　of　complex　arithmetic　in　control　system　is　simplified　consumedly.　The　method　could　be　broadly　applied　in　practice　systems　for　its　simple　programming,　easy　realization　and　better　performance　criteria.