The northeastern edge of the Ulan Buh Desert, a core area of wind-sand disasters in northern China, relied heavily on the morphological characteristics and sand-blocking capacity of nebkhas to optimize windbreak and sand-fixation projects. This study focused on nebkhas dominated by five shrub species-Caragana korshinskii, Amygdalus mongolica, Oxytropis aciphylla, Kalidium foliatum, and Nitraria tangutorum to reveal their morphological adaptation strategies and sand-blocking mechanisms in multi-species coexistence zones through field observations and morpho-functional quantitative modeling. Methodologically, we established three 20m×20m plots for each shrub community, measuring 93 mature, independent nebkhas (22 for Caragana korshinskii, 20 for Oxytropis aciphylla, 25 for Amygdalus mongolica, 15 for Kalidium foliatum, 11 for Nitraria tangutorum). Key parameters included shrub height, length (along dominant wind direction), width (perpendicular to wind direction), and nebkha height, long axis, short axis. Derived metrics such as canopy area (elliptical estimation:Ag=[π(Lg×Wg)]/4), nebkha volume (semi-ellipsoid calculation:Vd=[π(Ld×Wd×Hd)]/6), and sand-blocking volume per unit canopy(V=Vd/Ag)were computed. Data were analyzed via Pearson correlation, regression models (SPSS 25), and visualized with Origin 2022, focusing on relationships between canopy traits and nebkha morphometrics. Key findings included that:(1) The sand-blocking capacity of the five species followed the order: Kalidium foliatum＞Nitraria tangutorum＞Oxytropis aciphylla＞Caragana korshinskii＞Amygdalus mongolica. Among them, Kalidium foliatum and Nitraria tangutorum exhibited the highest sand-blocking efficiency (0.65 m³ and 0.56 m³ per unit canopy area, respectively), attributed to the synergistic effects of canopy complexity(e.g., Nitraria tangutorum's 8.76 m² canopy and prostrate growth, Kalidium foliatum's jar-shaped crown) and morphological parameters (strong correlations between crown area and nebkha volume, R²≥0.6); (2) Despite having the smallest crown width area (0.32 m²), Oxytropis aciphylla achieved high sand-blocking capacity (0.31 m³) through dense branching, challenging the traditional "canopy dominance theory"; (3) Strong wind erosion drove nebkhas to adopt low-profile, near-circular morphologies (e.g., Nitraria tangutorum with an aspect ratio of 1.13, height 0.65 m), prioritizing horizontal expansion over vertical growth. Based on these findings, we proposed a "frontline-depth" gradient restoration model that strategically deployed Kalidium foliatum and Nitraria tangutorum in windward zones for efficient sand interception, incorporated Oxytropis aciphylla in transitional areas to enhance dune stabilization, and expanded Caragana korshinskii in protected rear zones to strengthen systemic resilience. A "front-rear echelon configuration" model is proposed. This study provided critical scientific guidance for plant selection and spatial configuration in aeolian restoration across arid regions, pioneering integration of canopy complexity into sand-blocking capacity evaluation.