The invention discloses a feature acquisition method and device for a social group, belonging to the technical field of big data. The method includes: obtaining an invitation relationship record and afriend relationship record of the social group; creating a group network structure; according to at least one of a user distribution feature and a cascade tree feature of the group network structure,obtaining a designated feature of the social group, the user distribution feature being used for representing the distribution of a member user and a friend user, and the cascade tree feature being used for representing the distribution of an inviter member user and an invitee member user. Not just only on the basis of the attribute feature of the social group, the designated feature of the social group is obtained on the basis of at least one of the user distribution feature of the social group and the cascade tree feature, in this way, the attribute feature of the social group is expanded,the diversity is improved, and the prediction accuracy is improved when the method and the device are applied to prediction of the lifetime of the social group.