Now, many enterprises accumulated a mass of data, which is distributed and heterogeneous. But most search engine and some integrated software, treating the query of heterogeneous and distributed data, often could not play biggest role. The query result also often had only "scope" but no "depth" and exited plenty of rubbishes. Traditional query mechanism was inflexible and hadn't point. So a kind of personalized query platform for heterogeneous data was given. In the research and implementation course, ontology technology was led into; as a domain model, ontology provides a common comprehension about the domain concepts and the hierarchy of the concepts; at the same time, its utilization also reduces the dependence on the comprehension technology of natural language. Firstly gave a definition of ontology, and denoted a conception object by a quintuple group, constructed domain ontology and then designed a personalized query platform based on ontology, in the following content, introduced the working process of the platform and characteristics detailedly, finally drew an conclusion that personalized query platform we designed not only assured the recall and accuracy of query but also satisfied different users' demands.