Enclosure and rehabilitation were effective approaches to restoring fragile ecosystems in desert steppes. To assess the restoration effects and trajectories of desert steppe ecosystem structure and function after long-term enclosure, we?investigated?their?responses?to environmental factors, including enclosure duration, precipitation, temperature, vegetation type, and soil properties. This study investigated the desert steppe ecoregion of northern China through a comprehensive meta-analysis of 165 Chinese and English publications(2000–2023). The research synthesized 7,109 experimental data points from 99 independent studies, encompassing 66 key attribute parameters across vegetation, soil, and microbial communities. The results indicated that after long-term enclosure and rehabilitation: (1) Vegetation structure (height, cover, and density), diversity (species richness and Shannon-Wiener index), and function (biomass, litter mass, and net primary productivity) were significantly enhanced by 30-50%, 10-15%, and 20-90%, respectively. Soil structure (aggregates), nutrients (moisture, total phosphorus, and total potassium), and microbial activity (carbon and nitrogen content, and soil respiration) showed significant improvements of 8-30%; (2) Vegetation structure and diversity showed significant recovery within the first 0-5 years of enclosure. However, full restoration of ecosystem functions and key processes–including above and below ground biomass, net primary productivity, soil moisture and nutrients, and soil respiration - typically required an extended period of 11-15 years. (3) Vegetation and soil recovery exhibited significant threshold effects temporally (4 and 10 years), with precipitation thresholds at 160 mm, 250 mm, and 290 mm, and temperature thresholds at 3.5 °C, 6 °C, and 8 °C; ecological restoration trajectories differed markedly across these threshold boundaries. After more than 20 years of enclosure and rehabilitation in desert steppes, above-ground vegetation recovered rapidly, but soil structure and function lagged behind, and the stability of ecosystem processes was not yet fully achieved. The restoration effects of ecosystems exhibited multiple environmental thresholds related to enclosure duration, rainfall, and temperature, and there were significant differences in the restoration effects and trajectories of different ecosystem attributes at these environmental thresholds. These could serve as reference points for adaptive management of long-term enclosed grasslands. For future comprehensive restoration and enhancement of multiple elements and functions at the regional scale, we recommend adopting an approach that combines ecological restoration with productive use under specific climates and vegetation types.