RF energy harvesting wireless sensor network (RFEH-WSN) is a recent active research field in the domain of wireless sensor network. The use of dedicated energy transmitter (ET) has further enhanced the controllability and practicability of wireless sensor networks. One issue worth researching in this kind of WSNs is how to configure a given number of ET to optimize transmission power and reduce energy consumption under the premise of meeting node energy requirements. Firstly, the ET placement and power optimization problem are formulated to make clear the optimization objective and constraints. Then two optimization schemes are proposed. One is a two-step optimization scheme by which the transmission power of ET will be adjusted after placing ET. Another scheme is a joint optimization of placement and transmission power based on particle swarm optimization (PSO). Simulation results show that the energy saving effect of the joint optimization scheme is more obvious than that of the other.