Abstract: A bidirectional selecting method, between service objects and service providers, includes the steps of: after acquiring an expression data about a user, acquiring at least intentional object in a corresponding object database based on the expression data and a background information of the user to obtain a processing result; and outputting the processing result, wherein when the user is a service object, the object database is a service provider database, wherein when the user is a service provider, the object database is a service object database.