Based on the real option analysis method, this paper makes an empirical analysis of the evaluation and optimization of the model, and analyzes the main factors of the investment value of photovoltaic power plants in combination with the investment decision-making characteristics of photovoltaic power plant projects under the background of marketization. The electricity price and generation income, transaction price and income are all processed by geometric Brownian motion, and the random process is obtained by Monte Carlo simulation method. Based on the sensitivity analysis of the uncertain factors of the model, the investment risk of photovoltaic power station is evaluated and the suggestions are put forward. The results show that when the on-grid electricity price increases by 10%, the net present value is about 6 million yuan in the 26th year. Therefore, how to evaluate the uncertainty factors of photovoltaic power plant investment and make scientific and reasonable investment decisions is of great significance for the development of photovoltaic power generation.