SOFC/battery/PV hybrid energy system is widely used to generate electricity. However, it is challenging to manage output power of each devices while regulating the bus voltage within a safe range. To this end, this paper proposes an optimal droop control strategy for the hybrid system, which consists of solid oxide fuel cell (SOFC), lithium-ion battery and photovoltaic (PV) array. First, a group of nonlinear and implicit differential equations including different sources and controllers is developed. Then, multi-objective genetic algorithm is adopted to minimize the output power error and the electricity loss simultaneously, deriving the optimal droop control parameters as well as the feedback PI parameters. Finally, the optimal solution is chosen from the Pareto front. Numerical experiments demonstrate that the control performance of the proposed method is better than the single objective method while the electricity loss can be reduced by 96.26%..