Traditional dwellings are basically built by the villagers, and the light environment design of the building is rarely considered. Therefore, the indoor lighting effect is poor. In order to improve the light environment of traditional dwellings, a light environment experiment was carried out on a representative Miao dwelling in Huangtu Village, Danzhai County, southeast Guizhou, and the light environment was studied in combination with the spatial characteristics of the dwellings. The results showed that the daylighting performance of the main rooms did not meet the requirements of standard for daylighting design; the size and position of daylighting windows, the form of interior space, and the reflective properties of surface materials all have an impact on the interior light environment. Quantitative analysis of various influencing factors was conducted by software simulation, and the premise of light environment transformation is to minimize the impact on the original architectural features and spatial structure. Thus, the strategies of light environment comprehensive optimization of traditional dwellings were put forward from adjusting the size and quantity of lighting windows, increasing the roof daylighting tiles and daylighting windows under the eaves, paving light color wallpaper, setting adjustable reflective louver, et al. The results of the study can provide reference for the protective transformation of interior lighting environment of traditional dwellings and the daylighting design of new dwellings.