In OpenRoads Designer software on the Bentley platform, the logic of the underlying file is sorted, and its configuration method is studied and explored in depth, which can solve the problems of the enterprises and designers to allocate the basic BIM software resources and related settings according to the requirements. Firstly starting from the overall content of ORD underlying configuration, its structure is sorted out, and then the important configuration contents are overviewed mainly including the cell library, dgnlib file (civil unit, color table, design specification, display style, feature definition, graphic filter files, etc.). The underlying resources commonly used by designers are explained in detail. In addition, the current problems that need to be solved in the OpenRoads Designer underlying configuration file are sorted out. It is expounded that the solution of this part of problems brings the benefit to the BIM design of road.