Abstract: Designs dynamic query control based on multi-table and uses in query system,solves some defects including poor flexibility,difficult maintainability and low reusability of the traditional static query method and less query information and the poor data independence in previous dynamic query method based on a data table,makes user query the correlative data items,and provides the detail information.The query method not only makes user to compare and analysis data,but improves the efficiency of the system development.The test result show the performance of the query sub-system is good too.