Compares the fieldbus technology of PROFINET with PROFIBUS, and analyzes the application of PROFINET and PROFIBUS in the centralized air supplying control system. Practice proves that PROFINET overcomes the shortcomings of PROFIBUS control network, such as low-speed, complex and difficult to diagnose etc., and it has advantages of the system response quickly, good tracking performance, fast fault location and simple maintenance etc.. PROFINET network control is fully applicable to the production process such as the centralized air supplying and other complex control. It is valuable in practice.