Abstract:  In wireless relay systems, considering the source and relay nodes are both energy-harvesting and bidirectional energy cooperation is allowed between these nodes, for the scenario of Rayleigh fading channel, an power allocation algorithm was put forward to solve the optimization problem of the systems throughput by jointly optimizing the source and relay transmit power and the amount of energy transferred. In this paper, the system model was firstly established and convex optimization knowledge was used to obtain the optimal solution assumption. Ideal power allocation scheme was firstly proposed when assuming that there is no consumption in energy transfer process. Based on the scheme, the transmit power and the energy transferred were optimized again under the causality constraints on both energy and data. The simulation results show that the power allocation algorithm proposed in this paper is superior to other power allocation algorithms and can effectively improve the system throughput.