Grassland desertification on the Qinghai-Tibet Plateau (QTP) threatens ecosystem functions by disrupting nitrogen (N) cycling, soil structure, biodiversity, and the sequestration of soil organic carbon (SOC). Although nature-based restoration approaches, such as strategic fencing, re-establishment of native grass species, and longterm organic manure application, are increasingly employed, their cumulative effects on plant-soil-microbial synchrony remain unclear. This study assessed restoration outcomes across an eight-year chronosequence, relative to degraded (DL) and undegraded grassland (GL) controls, on the Zoige Plateau. Restoration gradually shifted vegetation from single-species in DL to diverse communities resembling GL by year eight, with marked increases in cover and biomass. SOC and N accumulation peaked in year six (7.70 Mg C ha-1 yr-1 and 0.49 Mg N ha-1 yr-1, respectively), followed by a slight decline, indicating a shift toward ecosystem stabilization. Improvements in soil aggregation and hydraulic properties mirrored the dynamics of vegetation. Multivariate analyses revealed that restoration success was contingent on the re-establishment of plant-soil-microbial synchrony. Microbial biomass, enzyme activity, and nutrient cycling recovered alongside vegetation, creating positive feedbacks that promoted macro-aggregate formation and SOC stabilization. Notably, nitrate availability served as a critical mediator, linking plant diversity with microbial attributes and stabilization of organic matter. The coordinated recovery of plant-soil components underpinned ecosystem resilience during later restoration stages. These findings demonstrate that nature-based restoration facilitates functional recovery by re-coupling plant-soil-microbial interactions, with nitrate serving as a key regulator. This synchrony-based framework provides mechanistic insight for reversing alpine grassland desertification in semi-arid QTP.