Aiming at the problem of limited transmission range and intermittent connection of nodes in underwater optical wireless sensor network(UOWSN), a network node localization algorithm is proposed by using multi-hop communication to expand the transmission range to enhance network connectivity. Firstly, the UOWSN is modeled as a three-dimensional(3D) random scaling model graph, and the connectivity probability expression of the network nodes under the model is derived according to the number of network nodes, communication range and optical divergence angle. Then, the received signal strength (RSS) location algorithm modified distance vector hop(DV-Hop) localization algorithm is used to solve the localization problem of network nodes, and compared with the existing schemes. The simulation results show that the performance of the proposed localization algorithm is significantly better than the standard DV-Hop algorithm and Hybrid DV-Hop algorithm.