Wenshan City, situated in the southwest of China, exhibits a typical karst mountain terrain. It constitutes a crucial ecological function area in China, featuring a fragile ecological environment and a high susceptibility to ecological variations. Grounded on the attributes of the karst mountain landscape, this paper has erected a target-comprehensive-project-index assessment index system for landscape ecological security. By employing the geometric mean and the InVEST model, the ecological sensitivity and significance of system services were appraised at two comprehensive levels. Subsequently, the ecological security target level was evaluated, ecological functional zones were demarcated, and differentiated management measures were proffered. The findings suggest that: (1) The regions highly susceptible to soil erosion, geological disasters, and rocky desertification are predominantly distributed in the eastern and southern areas; Water conservation, soil conservation, and biodiversity conservation were generally inadequate, and the regions of greater significance were mainly situated in the southwest. (2) The outcomes of the integrated ecological sensitivity and significance of system services disclosed that the ecological quality of the southwest region surpassed that of other regions; The overall level of landscape ecological security is low, with a general tendency of being high in the southwest, low in the east and south, and mediocre in the north. (3) The ecological function zone of Wenshan City was categorized into four types of ecological function zones, namely the rock desertification ecological function restoration zone, the urban ecological coordination construction zone, the biodiversity functional protection zone, and the water conservation and soil conservation function enhancement zone. Rational management measures and suggestions were advanced based on the ecological predicaments of each region.