With the development and popularization of the network and 3G wireless network technologies, special network technology constituted by 3G or GSM has become more mature using the 3G or GSM. The use of VPN network communication becomes more and more urgent. To constitute wide area network in a relatively remote and distributed hydrological station building, not only cost largely but also is a difficult work. By means of internet, via L2TP VPN encryption technology in construction of hydrologic virtual network, can not only solve the hydrological station network in real time flood forecast, but also realize the internal resource sharing, and internal office automation system access of the dispersed sites in the absence of special internal network. After nearly a year of the production run, Shandong hydrology, water level station reporting effectiveness greatly increased, the error rate was almost zero, gained apparent benefit.