Abstract: The Taihang Mountain is the natural ecological barrier of the Beijing-Tianjin-Hebei region. It is strategically important to assess risk to the Taihang Mountain ecology to ensure water security and assess its ecological function in the Beijing-Tianjin-Hebei region. This study established a classification system for the “Production-Living-Ecological” space land, and explored the characteristics of the “Production-Living-Ecological” land transformation in Pingshan County, a typical county in the Taihang Mountain. The landscape ecological risks in Pingshan County were explored using the landscape ecological risk evaluation method, and the contribution of land use transformation to the change in landscape ecological risk was measured. The results showed that: 1) from 1990 to 2018, the ecological land in Pingshan County decreased significantly, whereas the production and living lands increased significantly. The production and living lands were mainly transformed from ecological land, and the transformation areas were mainly distributed along the road and around the water area. 2) Areas with escalated landscape ecological risk in ecological land were mainly located in high-altitude areas in the central and western parts of the study area, and it is necessary to scientifically delineate the ecological protection redline and strengthen the ecological protection of these deep mountain areas in the future. Areas with escalated landscape ecological risks in production land were mainly located in the low mountains and hilly areas in the northern and eastern parts of the study area, where more attention should be paid to the protection and efficient use of cultivated land in the future. In contrast, the areas with escalated risk in living land were mainly located in the southern part of the study area, where the utilization of land resources should be adjusted, and the use of tourism resources should be scientifically planned in the future. 3) The contribution of land use transformation types to the change of landscape ecological risk in the Pingshan County varied greatly (0−29.97%), among which the risk of “transformation from ecological land to production land” made the greatest contribution. The results of this study can provide valuable reference information for promoting the coordinated development of the “Production-Living-Ecological” land use in Pingshan County and exploring green development and optimization of land space structure in the Taihang Mountain.