The invention relates to a multidimensional risk assessment method. According to the method, risks are analyzed and calculated by adopting the method of combining a qualitative mode and a quantitative mode, and comprehensive risk analysis is carried out from multiple dimensions such as safety strategies, management risks, technical risks and operation and maintenance risks. According to the multidimensional risk assessment method, from the perspective of information security management of the power industry, the four dimensions of strategy, management, operation and maintenance and technology are taken into full consideration, the risk assessment method integrating the four dimensions is achieved, a three-dimensional risk calculation model is established, and the multidimensional risk assessment method is mainly used for solving the problem of flattening and simplification of quantitative assessment in risk assessment of an electric power information system.