Energy harvesting gives a promising way to deal with the power constrained problem by harvesting energy from the external environment. In this paper, the multi-hop wireless network is considered where the relays with energy storage equipments are random scattered in several discs. The chosen relay nodes are used to decode-and-forward(DF) the received signals to the next terminal. The other active nodes in the discs harvest energy from the received signal. With the aim to achieve the minimum system outage probability, the close-form expressions are proposed about the optimal disc locations and about the optimal number of hops, respectively.