In order to overcome the defects of two ways above, to realize more effective integration of heterogeneous information source, third method is used in this paper First of all, information analysis of original application system is made to establish a unified standard format of data exchange, which is applicable to various kinds of information in all application systems. Via creating XML documents and XML schema, the corresponding relation between information source of some application system and standard format is expressed properly. According to these corresponding relations, by using professional data transform tool, data definition types of information application system are converted into unified standard format, and imported into the internal information resource database. The integration model is shown in Figure 2.