Abstract We use ERA5 atmospheric reanalysis data to study the fine temporal variation of the ZTD elevation scale factor and to construct a vertical profile grid model(YZTD-H model) of the ZTD in the Yunnan-Guizhou-Sichuan region that considers the fine temporal variation of the elevation scale factor. We test the accuracy of the YZTD-H model with the layered ZTD data of radiosonde stations in the Yunnan-Guizhou-Sichuan region as reference values. We compare the results with the GPT2w and the GPT3 models. The results show that the YZTD-H model, which considers the delicate time variation and vertical profile variation shows great stability both in time dimension and vertical profile dimension.