The invention discloses a power grid electric power operation project determination method and system. The power grid electric power operation project determination method comprises the following steps: establishing a power grid business performance analysis prediction model comprising to-be-analyzed input indexes and a target index, wherein the to-be-analyzed input indexes are parameters included in an electric power operation project; setting the selected value of the current to-be-analyzed input index, wherein the values of other to-be-analyzed input indexes are the reference values respectively; determining the values of the current to-be-analyzed input index as the corresponding output values of the target index with the selected value; determining the elastic coefficient of the current to-be-analyzed input index to the target index according to the selected values of the current to-be-analyzed input index and the corresponding output values of the target index; according to the elastic coefficients and risk preferences corresponding to the to-be-analyzed input indexes, determining the combining scheme of different values of the to-be-analyzed input indexes and regarding the combining scheme as the determined power operation project. According to the combining scheme, the setting of parameter values in the power operation project is more reasonable, the determined power grid electric power operation project is more suitable, and the power grid performance is improved.