Sensing data gathering is an important and fundamental issue in the Internet of Things (IoT). However, for battery-powered sensors, energy depletion is unavoidable. Using mobile sinks to collect sensing data by one-hop transmission is an effective way to prolong the lifetime of wireless sensor networks but will inevitably cause an excessive long delay time of data gathering. In order to reduce the delay time of mobile data gathering, it is necessary to incorporate multi-hop transmission into mobile data gathering. In this paper, a new mobile data gathering algorithm with multi-hop transmission is proposed to reduce the delay time of data gathering. The proposed algorithm is called the Bounded Relay Combine-TSP-Reduce (BR-CTR). The BR-CTR algorithm visits the convergence area of sensors’ communication ranges to reduce the number of visiting points. The BR-CTR algorithm is integrated with a path adjustment mechanism, which can further shorten the planned traveling path effectively. In performance evaluation, we compare the BR-CTR algorithm not only with the existing mobile data gathering algorithms with one-hop transmission but also with the existing mobile data gathering algorithms with multi-hop transmission in terms of the length of traveling path, delay time, network lifetime and buffer size requirement. Experimental results indicate that the proposed algorithm has high performance on all the above-mentioned indices.