In order to meet the requirement of high localization accuracy and the high reliable localization in some scenarios, the user nodes to be located were taken as a group to get better localization performance by utilizing the mutual distance information among them. A mobile group localization method was designed based on extended Kalman filter, which can alleviate the influence caused by environmental noisy and unstable wireless signals. Besides, a real system was implemented and experiments were performed on the campus of University. The experimental evaluations prove that the performance of the proposed method can effectively improve the localization accuracy.