The invention discloses a plug-in type smart energy system development method, a development platform and a smart energy system. The method comprises the steps that the classification is conducted according to business types and functions achieved in specific applications of the smart energy, the business types with correlation or demand types with function requirements are classified into a subset, and the specific applications of the smart energy are divided into a plurality of subsets on the basis of the business types or the demand types with the function requirements; the independent plug-ins are designed for the various subsets respectively, each plug-in is independently developed, and each developed plug-in can independently achieve one or more functions; according to the differentrequirements of users, different plug-ins are selected to be combined and packaged, and the plug-in type smart energy system required by the users is formed. The plug-in type smart energy developmentplatform can be self-organized, can realized the plug and play effect, is strong in expansibility, supports the distributed deployment, is convenient to maintain, and solves the problems that a traditional development platform is low in development efficiency, poor in expansibility, low in stability, high in maintenance cost and the like.