Device-to-device (D2D) communication is a promising technology for 5G mobile communication networks due to several benefits such as highly increased spectral efficiency, extended coverage, reduced latency, and enhanced cost and power efficiency. However, the multi-hop routing protocol faces many challenges in the D2D communication. In this paper, a social-aware routing algorithm is proposed to design the multi-hop path in the cellular network. Based on the Friis transmission equation, we drive the received power distribution and construct a relay cellular network. In addition, the congested ratio and average congested intensity are important indices to measure network congestion. To investigate the impact of network congestion on the end-to-end delay, we evaluate the performance of the proposed algorithm in three different congested ratio networks. Simulation results show that the proposed algorithm outperforms the conventional algorithm in terms of reducing the end-to-end delay.