The invention provides a three-layer target energy internet planning method and device, and the method comprises the steps: analyzing the conditions of an electric load and a thermal load according toan energy demand, determining an energy supply mode according to resources and infrastructure conditions, and designing an energy infrastructure matched with the energy demand. Generally, the energydemand maximum day (such as the maximum load day in winter and the maximum load day in summer) is used for power balance. Various unit constraint conditions (such as minimum operation load of a generator set, power of energy storage equipment and efficiency of a heat pump unit) and operation modes (such as 24-hour running or only running at a specific time period) are considered. Investment, operation and maintenance, depreciation cost and various energy boundary conditions (such as purchase price, sales price and subsidy price) of various units are combined, economy, energy utilization efficiency, environmental benefits and the like are taken as optimization objectives, and configuration of the energy infrastructure is obtained.