Between each node database there must be all different in the distributed heterogeneous database, so how to resolve these differences (It’s said that realize the mutual transformation between heterogeneous databases) was an basic problem in the heterogeneous database integration, synchronous and optimized. This paper analyzes the conversion mechanism for the distributed heterogeneous database between node databases and the realization of the conversion module theoretical includeing the conversion information extraction module, structural conversion module, structure formation module and put forward a concrete realization solutions.