With the significant increase of computation-intensive and latency-intensive applications， Mobile-Edge Computing （MEC） was proposed to provide computing services for users at the network edge. In view of the limited computing resources of edge servers at the Base Stations （BSs） and the long latency of long-distance computation offloading of users at the network edge， a multi-user computation offloading and resource optimization policy based on Device-to-Device （D2D） communication was proposed. The D2D was integrated into MEC network to directly offload tasks to neighbor users for executing in D2D mode， which was able to further reduce offloading latency and energy consumption. Firstly， the joint optimization problem of multi-user computation offloading and multi-user computing resource allocation was modelled with the optimization objective of minimizing the total system computing cost including latency and energy consumption. Then， the solution of this problem was considered as a D2D pairing process， and the multi-user computation offloading and resource optimization policy algorithm was proposed based on stable matching. Finally， the optimization allocation policy of D2D offloading was solved iteratively. The characteristics such as stability， optimality and complexity of the proposed algorithm were analyzed by theoretical proof. Simulation results show that， the proposed algorithm can effectively reduce the total system computing cost by 10%-30% compared with the random matching algorithm， and the performance of the proposed algorithm is very close to the optimal exhaustive search algorithm， indicating that the proposed policy based on D2D offloading is helpful to improve latency and energy consumption performance.