Message forwarding in opportunistic mobile networks (OMNs) is constrained by node mobility, limited resources, and sparse distribution, for there are not stable communication links among nodes. Selecting nodes as relay is critical for routing performance. In order to identify suitable relay nodes for enhancing messages delivery efficiency, many social-aware routing are proposed. However, node social relationships change over time, they are not be fully considered in most social-aware algorithms. In this paper, we present a routing algorithm based on the importance of node social relationships. Firstly, we evaluate the significance of node social relationships from the quantity and quality of social interactions. Subsequently, nodes with higher social importance are selected as relay nodes for message forwarding in our paper. Empirical results demonstrate that our algorithm compared with the TA2HA algorithm, Epidemic, Spray and wait, and Prophet has better performance in terms of diminishing network latency and upholding superior message delivery rates.