The invention provides a wallboard modeling method based on the UDF technology. UG software is adopted as a modeling platform, and a UDF library is set up; a parametric feature model of a wallboard is set up, the feature dimension variable and preliminary sketch dimension variable of the wallboard are determined, and the wallboard modeling method comprises the following modeling steps that a UDF is generated according to the feature dimension variable and preliminary sketch dimension variable of the wallboard; a user interface and a shortcut button for calling the generated UDF are developed through a UG/OPEN API module; a generated program is operated, and the needed wallboard model is generated by changing the values of all parameters in the user interface. According to the wallboard modeling method based on the UDF technology, the programming workload of library establishing is reduced, subsequent expansion and modification of the model in the library are convenient, the good user interface can be obtained, a system is connected with the model library, automatic normal data selection is achieved, the operation of calling the model in the library is convenient and fast, and subsequent modification and expansion of the content of the library are very convenient through the open model library structure.