Abstract: To solve the energy efficiency problem of sharing the cellular user resources in Device-to-Device (D2D)-based cellular-vehicle to everything (C-V2X) communication system, an energy efficiency optimization algorithm is proposed, where a new power control approach is presented to maximize the total energy efficiency of the vehicular-users (V-UEs) and the energy harvesting technology is utilized to improve the energy efficiency of the V-UEs. In the proposed algorithm, reducing the number of constraints through using Lagrangian multiplier method, the modified Dinkelbach method is utilized to convert the original problem into an equivalent subtraction optimization problem, and the range of V-UE power control is obtained. Finally, the numerical simulation results show that the proposed algorithm can obtain the optimal energy efficiency within different distances between V-UE users.