In farmland environment, unstable network link quality which caused by the multi-scale signal propagation effect may lead to low data aggregation efficiency. An improved energy aware opportunistic routing of farmland WSN is proposed in order to match the network energy consumption constraints. The nodes priority in the forwarding list is set according to the distance between nodes and the residual energy and energy consumption. In this case, the network performance such as data throughput, high transmission reliability could be satisfied. The network the energy consumption may be reduced and balanced. Simulation is taken between different algorithms, the results show that the network average power consumption is reduced and the network lifetime is prolonged.