The invention discloses a social circle digging method and device based on microblog interactive relationships. The method includes the steps of A, acquiring a collection of microblog users interacted with a target microblog user; B, building a user relationship topology map according to the interactive relationships, digging to obtain totally-linked sub-maps, calculating utility value of each totally-linked sub-map and saving; C, aiming at each totally-linked sub-map, generating an expansion microblog user collection according to the interactive relationships; D, acquiring the microblog users which are interacted with an optional microblog user in the microblog user collection and do not belong to the microblog user collection, adding the microblog users to the saved totally-linked sub-maps; E, calculating the utility values of the added microblog users after and before being added to the collection, adding the microblog users to the new collection if the utility values increase; F, judging whether microblog user selection is completed or not, if not, traversing the expansion microblog user collection, returning to the step D, or else, forming the social circle collection. By the method, the social circle and interest circle of a user can be dug.