The invention belongs to the network information propagation detection technology field and discloses a method for detecting the social network information explosion. The method comprises steps of collecting a social network structure and a content generated by a user, constructing a user topic propagation probability matrix, obtaining messages which are published or forwarded by users from the social network, constructing an information propagation track according to the information forwarding identifier and time information, constructing an information propagation matrix according to the topic transmission probability, and analyzing the probability of information explosion according to the information propagation track and the information propagation matrix. Besides, the invention also provides a social network information explosion detection system for realizing the method. As a result, the invention can effectively predict whether the social network information to propagate in an explosion manner.