In this paper, an association method for IWSNs (industrial wireless sensor networks) using dynamic hysteresis is proposed. The energy consumption of the nodes can be effectively managed by a decrease in the response packets of the neighbors under the joining requests of the mobile nodes. However, static hysteresis causes a decrease in the joining period for preventing the ping-pong phenomenon. In order to optimize the association rate, dynamic hysteresis is used for the proposed method. To evaluate the performance of the proposed scheme, the association rate is investigated and analyzed through computer simulations. Simulation results show that the proposed method enables efficient joining according to the mobility of nodes in IWSNs.