The computation offloading problem in Multi-access Edge Computing (MEC) has become one of the current important research topics. Most existing computation offloading solutions mainly focus on the offloading within the edge and terminal structures. This paper proposes a new computation offloading scheme that considers the resource utilization of cloud servers in edge computing, treating cloud servers as supplements to edge server resources. This approach can alleviate insufficient computing resources of edge server. Additionally, we establish a Stackelberg game to solve the computation offloading problem, and then analysis the strategies of cloud servers, edge servers, as well as mobile devices. Then, we determine the optimal strategies for all participants and prove the existence and uniqueness of Nash equilibrium solutions in the game. Simulation results and analysis also validate the feasibility of the computation offloading scheme based on Stackelberg games. The proposed method is more efficient and suitable for scalable edge computing environments compared with the two existing offloading schemes.