The invention relates to a power grid capital construction project dynamic early warning identification method and system, and the method comprises the following steps: analyzing the current situationof power grid capital construction project dynamic early warning, and building a power grid capital construction project multi-dimensional target time sequence prediction model; establishing a powergrid capital construction project early warning index library, and constructing a power grid capital construction project three-level key early warning index library and an index influence structure diagram by utilizing the interpretation structure model; collecting engineering data of the power grid capital construction project to be evaluated, drawing a dynamic early warning curve of the power grid capital construction project, and determining a dynamic early warning threshold value of the power grid capital construction project; and based on a multi-dimensional target time sequence prediction model and mapping and membership relationships between different levels of the dynamic early warning curve and the three-level key early warning index, constructing a top-down or bottom-up bilateral linkage deviation checking mechanism, and carrying out dynamic early warning on the power grid infrastructure project. The method can be widely applied to the field of power grid capital construction project dynamic early warning.