Starting from the basic hypothesis analysis of TOPMODEL, the physical concept and overall structure of the model are discussed, and the differences between the traditional lumped model and distributed hydrological model are compared, pointing out that the TOPMODEL model is more appropriate than the traditional hydrological model for the simulation of the actual hydrological process, and it is easier to update the data, and it is simpler than the distributed hydrological model, with fewer preferred parameters and easy to use. At present, the development of TOPMODE model theory and application at home and abroad mostly focuses on the change of parameters and the form of basic equations, and some theoretical issues need to be further studied, such as the adjustment of model microstructure and topographic index calculation method in specific application.