Recently, the Underwater Wireless Sensor Network has become the significant branch in the field of wireless sensor network, which extend people's research into the underwater. However, because of the particularity of underwater circumstance, such as Mobility, high error rate and a low transmission rate etc, makes the Traditional land-based sensor network technology unsuitable for underwater application. Inspired by the Six Degrees of Separation, the article put forward the NIR: UWSN Routing Protocol Based on Node Neighbor Information, which chooses the next step via Greedy Strategy, and the ones with more neighbor node are given a higher rate. The simulation results show that NIR energy costs may remain at a relatively low level.