The increasing number of electric vehicles presents opportunities for investment in public charging stations, but uncertainties such as competition and electricity price fluctuations elevate the risks associated with these investment projects. Considering the random fluctuations in the marginal contribution per unit of charging and the utilization rate of charging stations, a real options model is constructed. By solving this model, the investment threshold for charging stations under the condition of maximizing expected investment value is obtained. Using this investment threshold condition, investment strategies are discussed in two scenarios: random fluctuations in charging service fees and the integration of energy storage systems. The research findings indicate that: 1) Uncertainty in the external environment significantly delays investment in charging stations, highlighting the importance of policies to ensure relative stability in the investment environment; 2) The waiting time for charging station investment is determined not only by external environmental uncertainty but also by initial returns, suggesting that ensuring a minimum return for charging stations is an effective way to incentivize investment; 3) Whether energy storage investment is advantageous depends on the additional investment amount and the marginal contribution per unit of electricity. Specifically, when the proportion of energy storage investment is relatively small, increasing such investment may help promote investment in charging stations.