Power system dispatching and control are facing a problem of overall planning and close coordination. The equivalent simplification of the external power grid is the premise and key to the smooth implementation of decision making. One of the key problems is the equivalent simplification of the power grid. In the traditional equivalent simplification method, the increase or deletion of "source", "network" and "load" of equivalent value power grid has changed its structure, active quantity and passive momentum. This makes the accuracy of dispatching and control face challenges in the process of global planning. Therefore, in the power grid panoramic environment, the deep aggregation power grid model, solution method and its application are proposed. First, the aggregation method of power plants and connecting stations is given to form an aggregated power grid model. Second, a deep aggregation power grid model is established by integrating power plants and stations into transmission lines. Third, the functional relationship between the unknown quantity and the adjustable quantity (generator power) of the deep aggregate power grid model is derived, and the long-term and short-term memory network is used to analyse its parameters. Finally, an economic dispatching application is taken as an example to verify the effectiveness of the proposed method. This work is supported by the National Natural Science Foundation of China (No. 51477091).