Abstract: A network slice mapping algorithm based on priority and shortest path (PSP) was proposed to solve the problem of long queuing time of high-priority network slices in the process of network slice mapping. The network slice queuing model is modeled as a priority task queue model, and the queue is divided into two queues of high priority and low priority, the mathematical model of the network slice mapping problem is established, and the optimization objective is defined as the network slice delay,the network slice mapping problem is divided into node mapping sub-problem and link mapping sub-problem for solving. In the process of node mapping, the greedy algorithm was adopted to allocate resources with higher performance to network slices with higher priority, and the virtual network functions were mapped to corresponding devices. After the node mapping was completed, the shortest path algorithm was used for link mapping. The experimental simulation and result verification analysis of the PSP algorithm show that the PSP algorithm not only significantly reduces the processing delay of the high-priority network slice, but also reduces the overall delay of the network slice.