The invention relates to a contribution type group key management method in security group communication. The method comprises signature and authentication of group members, own contribution of the group members to generation and management of keys, and independence and full forward security of the keys. A key tree is organized into a tree topology structure including a main tree, a join tree andan exit tree; the join tree is used as a cache region for accepting new members; and when the join tree reaches a certain height or members exit, members in the join tree are moved and merged into themain tree in batches. New members joins to a root part of the join tree, so that time complexity when the members join is reduced, and an approximate progressive upper bound of member join time costis reduced to O(1). when members exit, the exit tree is introduced, and the exiting members are moved to the exit tree, so that average cost is reduced, and an approximate progressive upper bound is reduced to O(1). According to the invention, when secret communication is carried out among mobile group equipment in a network environment, security communication among the group equipment can be ensured; calculation and communication energy consumption is relatively low; and the contribution type group key management method has good flexibility, security and practicality.