The invention discloses a network detecting method using an intelligent network card, wherein the intelligent network card is serially connected with an exit of a local network or a small industry network, and stores an ACL (access control list) rule; a quintuple group ACL (access control list) rule of a server end is transmitted to an intelligent network card storing module by a network card management module firstly, then the intelligent network card receives network data and performs stream reverting treatment to the data; in a data processing module of the intelligent network card, the treated message is matched with the existing ACL (access control list) rule in the storing module, and corresponding actions of discarding, transmitting, marking, massage transmitting or log transmitting are adopted. According to the method, analysis and detection actions for the network data by the server is delivered to the intelligent network card for treating, so that the load of the background server CPU (central processing unit) is reduced effectively, and meanwhile, a plurality of standard compatible interfaces are provided, thereby enabling the existing associated network processing program to use the intelligent network card in seamless manner, and further developing the advantages of the intelligent network card on the analysis and detection of the network data. The method is suitable for various situations such as network detection.