The invention relates to a network windstorm restraining method of an intelligent substation process level IED, and belongs to the technical field of electrical power system substation automation. According to the method, the network data transmitting and processing procedure of a merging unit device is utilized, a hardware module, a network drive module and an application module are controlled to receive and process message data, three-layer network protection is achieved, and the purposes that the data processing and device performance of other sets of an Internet port cannot be affected by the abnormity of data flow of a set of messages of the Internet port and the data processing performance of other Internet ports and the performance of the whole device cannot be affected by the abnormity of the data flow of one or several Internet ports are achieved. When the pressure of some sets of network messages of one Internet port is abnormal, other sets of messages of the Internet port cannot be affected. The possibility of device moving refusing or mistaken moving is eradiated under the bad network environment, and the reliability of device running is guaranteed.