Guizhou province, situated in the heart of the Karst region in southwestern China, faces significant ecological fragility due to the intense human-environment conflict, resulting in severe ecological damage and posing challenges for restoration efforts. This study focuses on addressing the current issue of ecological restoration, particularly related to the shrinking of ecological source areas, in Bijie City, a typical mountainous city in the southwestern Karst region. To achieve this, morphological spatial pattern analysis (MSPA) and landscape connectivity indices are employed to identify ecological source lands. Additionally, the Minimum Cumulative Resistance model and circuit-theory based connectivity analysis are utilized to extract ecological source areas and corridors, among other features, which are then graded accordingly. Subsequently, using the “Linkage Mapper” tool, critical ecological nodes are identified to pinpoint areas in Bijie City that require ecological restoration. Based on the research findings, ecological zones are determined, and corresponding restoration strategies are proposed for Bijie City. The results indicate that: (1) Bijie City encompasses 62 potential ecological source lands, covering a total area of 3944.37 km2, with 26 critical ecological source lands spanning 2643.35 km2, and 36 general ecological source lands covering 1302.89 km2. (2) A total of 147 ecological corridors, measuring 1333.99 km in length, are extracted, including 45 critical corridors spanning 353.44 km, 65 important corridors covering 869.15 km, and 37 ordinary corridors spanning 111.39 km, which can potentially form an ecological network pattern. (3) Fifty- four key ecological restoration areas are identified, comprising 23 key ecological pinch points and 31 key ecological barrier points. Consequently, it is recommended to divide Bijie City into key conservation zones, buffer zones, controlling zones, optimization zones, and corridor restoration zones for effective ecological restoration. Moreover, based on MSPA and other digital analyses, critical points are proposed to optimize the ecological security pattern in Karst areas.