Abstract: In view of the defects existing in present engineering data models for the road bridge construction problem solving, the function graphic data model is provided. Taking the function graphic modeling technology as the instruction, with the feature line and the feature line array as the basic data structure, this paper introduces the length-variable and unstructured engineering graphs, conducts the related graphic and professional computation, describes the collaborative relationship among feature line arrays, and the model supports dynamic computation process for function graphic objects. The result proves it a new way to create complicated engineering graphic objects with simple data structure and its engineering application value in engineering software development.

Key words: computer application, data model, function graphic object, road bridge construction problem