Dynamic geometry software is widely applied to geometric constraint constructions because it is dynamic and intuitive. Aiming at a problem that the data structures in the field of dynamic geometry lack reusable abstract descriptions,a design method of the dynamic geometric software domain model was proposed. Firstly,the basic context boundaries were identified and outlined by means of domain analysis. Then,a dynamic geometry software core domain model was designed through the domain model. Finally,the dynamic geometry software was decoupled in both vertical and horizontal dimensions during the architecture modeling process. Experimental results show that the dynamic geometry software developed by using the design method of the proposed domain model can correctly deal with the graphic degradation situation at a critical position. The domain knowledge expressed by the model is applicable to 2D and 3D dynamic geometry software at the same time,and can design the layout and interaction for different devices respectively,thus a high-level reuse of the domain knowledge is achieved.