The invention provides a method for supporting a function of calling specific functions of a middleware database through a simple SQL. The method is characterized in that users have the highly customizable performance and the operation simplification on database functions. The method comprises the following steps of: (1), setting up an architecture; (2), creating an index file; (3), storing data in different databases; (4), querying and expanding; (5), querying and analyzing; (6), performing routing binding and distributing; (7), executing the method; and (8), packaging a result, and returning. By means of the method disclosed by the invention, in a distributed database environment, for specific functions of various node databases, users can realize unified calling through an intermediate management platform only by using simple SQL-like statements.