A representative communication standard of the Internet of Things(IoT) is a low cost ZigBee. ZigBee is suitable for using in a wireless sensor network. Because it operates based upon utilizing low power. However, if congestions occur in routers that make up the wireless multi-hop network, there can be a serious problem that the buffer of the routers overflows. In this paper, we propose a new algorithm that can be conserved the power to reduce the congestion that occurs in multi-hop wireless routers that make up the network using ZigBee. The results show that proposal algorithm's frame loss rate is 20% less than existing algorithm. Also power consumption gained the 12.5% through the problem how to make a group.