To excavate the ecological wisdom of Yangzhou classical gardens through the field test of Xiaopangu garden space and the thermal comfort evaluation by using the thermal environment evaluation model RayMan to calculate the equivalent physiological temperature (PET), this paper analyzes the change rules of air temperature, relative humidity, wind speed and other climatic factors in summer and daytime. It discusses the impact of the spatial form of classical gardens on the summer thermal environment in combination with the sky view factor (SVF). The research shows that the open space of Yangzhou classical gardens is exposed to more solar radiation, resulting in hot summer days and poor thermal comfort. On the other hand, the semi-closed area has strong spatial adaptability, and the elements of gardens should be reasonably allocated to improve the thermal environment. Because the closed space receives less solar radiation, the impact of the wind environment on thermal comfort should be considered. In addition, SVF is also one of the critical indicators of thermal environment evaluation, but it needs to be an accurate indicator. The shape and direction of the sky view also significantly impact thermal comfort.