Abstract: As the power assurance for high-speed railways, external power supply projects for electric railways possess both the common characteristics of power grid projects and the unique attributes of traction power supply, facing complex risks in the stages of investment decision-making, construction implementation, and commissioning operation. Based on analyzing the characteristics of external power supply projects for electric railways, this paper systematically identifies risk factors across the entire life cycle, constructs a risk assessment indicator system encompassing four dimensions: safety, cost, revenue, and effectiveness, and proposes a maximized differentiation combination weighting method and a risk coefficient evaluation model. Response strategies are formulated respectively for the three stages of investment decision-making, construction implementation, and commissioning operation. The research results can provide a systematic theoretical framework and practical guidance for risk management of external power supply projects for electric railways.