After system is initialized, electrical interface module of multiplexing 10/100/1000Mbps Ethernet, or optical interface module of multiplexing 1000Mbps Ethernet, or interface module of multiplexing ATM(over STM-1)PHY module convert data in current network to bus of media flow. Through bus of media flow, kernel process module of network processor extracts data to carry out pretreatment, sends datato switching module of Ethernet. Based on coincidence relation between kernel process module of network processor and module of main processor, the method forwards pretreated data to corresponding module of main processor, and carries out advanced treatment for received pretreated data. Introducing newest network processor to the interface module of monitoring system for communication protocol, the invention raises processing power of interface module, and enhances processing power of main processor module on large volume data through pretreatment on data in current network.