In DHT-based structured P2P ( Peer to Peer) networks,load imbalance occurs owing to the non-uniform distribution of objects stored at peer nodes,the heterogeneity nature of node capabilities and the dynamic characteristics of P2P networks. In order to solve this problem,a hierarchical load balancing model based on binary trees is established on the hypercube DHT overlay networks. The proposed model is used to collect the load and capacity information of nodes,develop the load balancing strategy and transfer the overloaded loads. In this model,by using the balancing domain,load balancing can be implemented in a parallel and distributed way. Simulation results show that the proposed scheme can achieve preferable load balancing in the environment of dynamic P2P networks.