The increasing passenger volume and the rapid development of the electric vehicle industry make the electricity consumption of the expressway service area grow day by day. It is of great significance to study the planning and design method of the microgrid in the expressway service area. This paper established a wind-photovoltaic-storage capacity planning model for the microgrid in expressway service areas, which considered the dust removal maintenance of photovoltaic panels. The multi-objective optimization problem was solved by the improved fast non-dominated sorted genetic algorithm (NSGA II) with the aim of minimizing the total system investment, and operating cost and maximizing the self-consistent rate of electricity consumption of the microgrid. The Pareto optimal solution frontier with uniform distribution and wide range is obtained, and the capacities of PV, wind power, energy storage, and contact line are obtained under different self-consistent rates of electricity consumption. This method can not only make full use of distributed PV resources that can be developed on the expressway to improve the self-consistent level of energy but also comprehensively evaluate the economy of the microgrid system and meet the requirements of power supply reliability.