Most grid services have adopted the centralized register and searching mechanism, currently. Those are easily led to single peer failure and access bottleneck. With expanding of the grid?s scale, P2P will become one of the primary frameworks of grid. Inspired by combining the grid with P2P technique, we focus on data resource searching mechanism in database grid on pure non-structural P2P framework, and an effective resource searching model(IBFS-HDI) is put forward, in which, a breadth first resource searching mechanism based on schema matching index routing (IBFS) is raised for reducing the routing filiations as earlier as possible and decreasing the number of peers accessed, while hierarchical top-k query and data integration mechanism(HDI) for lessening the data transmission cost and improving the data integration efficiency. Finally, experiments demonstrated the effectiveness of the resource searching model, and database grid with IBFS-HDI can return satisfying results to user rapidly and efficiently.