The moisture recycling in oases is essential for understanding the sustainability of water resources and ecosystem stability in arid regions, including those in arid Central Asia. However, the contribution of oases is difficult to quantify because of the complex spatial heterogeneity in mountain-oasis-desert systems in Central Asia. Using the UTrack atmospheric moisture tracking model, we examine the role of oasis-generated moisture in regional water cycles in Central Asia and quantify the contribution of oasis evapotranspiration to precipitation in the past four decades. Our results indicate that oasis evapotranspiration contributes substantially to precipitation both within oases and in adjacent mountain water towers, and the annual contributions reach up to 100 mm in some mountain regions. Summer shows the highest proportional contributions due to intensified evapotranspiration, while winter contributions are negligible. Marked spatial heterogeneity exists among different oasis clusters: southeastern oases near mountains exhibit high localized contributions, whereas western oases display extensive moisture transport driven by the terrain and atmospheric circulation. During the past several decades, the contributions of oasis moisture recycling have increased (p < 0.01), which is consistent with the trend in oasis evapotranspiration. The oasis moisture recycling processes substantially enhance regional water availability and sustainability, thereby reshaping spatial patterns of water circulation. From a perspective of integrated water resources assessments and management strategies, oases should be recognized as non-negligible sources of atmospheric moisture in ecological restoration and sustainable water use in arid land.