According to the problems that the network monitoring commercial software is expensive and free tools software is insufficient, etc., this paper proposes a campus network equipment monitoring platform using open source software SNM (System and Network Monitor). The methods of monitoring network devices and reading network equipment MIB library are described, while the working principle of SNM server, the overall structure, the run environment configuration, objects, and the graphics configuration file structure are also introduced in details. Finally，the paper implements the real-time monitoring on the network device performance from Ping, sysUpTime, Network Usage, CPU, Memory, and other parameters, at the same time，the monitoring results are showed by PNG.