The invention relates to a network storm quick detection method and device. The method includes: comparing a time interval between a collected message and a previous message having same CRC (cyclic redundancy check) with a set time threshold T; when the time interval is smaller than the time threshold T, accumulating message flow corresponding to CRC; comparing flow after flow accumulation with a set flow threshold Fmax to judge a network storm. The method is simple in principle, and quick detection of the network storm is realized by utilizing a method of comparing CRC of Ethernet messages; detection is accurate, free of limitation of message type and flow and free of influence on receiving and processing of normal business messages, and a starting condition is provided for network storm handling, so that impact on equipment caused by the network storm is lowered or avoided.