Abstract: Device to device (D2D) communications help to improve the efficiency of data dissemination services in cellular networks, but the differences between D2D links are not considered fully, thus it limited spectrum resource utilization and the data transmission rate. In this paper, it proposed a device-to-device forwarding algorithm based on relay in cluster. By introducing relaying and forwarding during the multicast process, our method can provide the high-speed data services for the users with poor link quality. The simulation results and analysis show that our algorithm can effectively solve the problem of link difference which leads to the decrease of multicast efficiency, accelerate the data rate of D2D links, and improve the communication performance of the D2D network.