In the existing opportunistic networks, the probabilistic routing protocol does not take into account factors, such as buffer space of node, historical encounter information of node, which leads to low delivery rate, and an opportunistic network forwarding algorithm based on node utility value (FSNUV) is proposed. First, consider the average meeting interval time of nodes and the size of the free buffer space in the calculation of optimizing encounter probability. Then, the node utility value model is established based on the factors, such as encounter probability of node, the change rate of node, the transmission capacity of node and the connection capacity of node. Finally, the next hop node is selected according to the node utility value and the message value model is used to determine the sending order of messages, and the high value message is sent first. The simulation results on The ONE platform show that FSNUV can effectively improve the delivery probability, reduce the network overhead radio and average relayed times so as to improve the performance of opportunistic network.