The invention belongs to the technical field of the user behavior analysis of the computer network and particularly relates to an association method about the depth behavior based on the user connection diagram. The method includes the steps that the user connection diagram is constructed based on the IP address, the port number and the protocol number of the message in the network; the behavior association matrix is constructed based on the adjacent communication relation of the user according to the user connection diagram; the different user communities are divided and obtained by using the clustering method of the K means according to the behavior association matrix; the behavior identification of any user node in the user community is obtained based on the familiar port number and the common port number according to the user community; the whole behavior identification of the user community is obtained by adopting the majority voting method according to the behavior identification of any user node in the user community.