To enhancing the wireless sensor network’s security in target tracking and locating application, this article proposes a tracking cluster based mobile cluster distributed group rekeying protocol (MCDGR). Based on the given sensitivity, sensors can locate the moving object in the monitored area and form a tracking cluster around it. This tracking cluster can follow the target logically, process data on the target and report to the sink node, and thus achieve the tracking function. We introduce a multi-path reinforcement scheme, q-composition scheme and one-way cryptographic hash function based random key predistribution algorithm (RKP), which can guarantee a high accuracy and security and a low energy consumption on the same time in large-scale sensor networks. To enhancing the wireless sensor network’s security in target tracking and locating application, this article proposes a tracking cluster based mobile cluster distributed group rekeying protocol (MCDGR). Based on the given sensitivity, sensors can locate the moving object in the monitored area and form a tracking cluster around it. This tracking cluster can follow the target logically, process data on the target and report to the sink node, and thus achieve the tracking function. We introduce a multi-path reinforcement scheme, q-composition scheme and one-way cryptographic hash function based random key predistribution algorithm (RKP), which can guarantee a high accuracy and security and a low energy consumption on the same time in large-scale sensor networks.