Ultra-thin glass is used to renovate windows. The thin-glass triple-pane glazing with two cavities is developed， so as to investigate the impacts on the thermal performance of the windows by optimizing glass thickness， adjusting the number and position of low emissivity （low-E） coatings， and filling different inert gases. Firstly， hierarchical and K-means clustering methods are used to cluster glass types in the International Glazing Database （IGDB） to determine seven low-E glass types. Secondly， based on typical window frame structures， single or combined strategies such as inserting thin glass， adjusting the low-E coatings， and changing the filling medium are proposed. Then， based on WINDOW， THERM， and Optics， the thermal performance of thin insulating windows under different renovation strategies is analyzed， and a full-scale experimental platform is built to conduct experimental research on the thermal performance of thin insulating windows. Finally， the impact of different renovation strategies on thermal parameters is quantified by the E-FAST sensitivity analysis method. The results show that compared with low-E insulating windows， the heat transfer coefficient of the renovated thin insulating window can be reduced by 30.64%. The type of cavity medium and low-E coating are the key parameters affecting the thermal performance of thin insulating windows. Compared with the renovation method of replacing the whole window， the renovation method of using thin-glass triple-pane glazing for window renovation can reduce material costs by 83%~87%.