A long-term, stable cropland ecosystem is crucial for the sustainable utilisation of land resources and the reliable guarantee of food security. However, oasis-irrigated agriculture in arid and semi-arid regions continues to face ecological risks, including water constraints, soil salinisation, and desertification, as well as persistent pressures arising from irrational land-use practices, which limit the health and stability of cropland systems. This study focuses on the northern slope of the Tianshan Mountains (NSTM) in Xinjiang and, from the perspective of social-ecological systems, develops a two-dimensional evaluation framework integrating ecological stability and utilisation stability. Cropland ecological stability (CES) and cropland utilisation stability (CUS) over the past two decades were comprehensively assessed, and a spatio-temporal, two-dimensional risk matrix was further constructed to identify patterns of cropland system destabilisation risk, thereby providing a scientific basis for differentiated cropland management decisions. The results indicate that, from 2000 to 2020, CES in the NSTM exhibited a consistently increasing trend with pronounced spatial heterogeneity, and unstable cropland was mainly concentrated in highly fragmented, marginal areas. Overall, CUS in the NSTM remained relatively high during 2000-2020, but unstable utilisation was still concentrated in marginal zones, indicating the persistence of land-use pressure. The integrated risk assessment shows that low-risk cropland accounts for the majority of the region and is widely distributed across oasis plains and central areas with concentrated water systems, whereas medium-and high-risk areas are mainly distributed along oasis margins, suggesting that cropland systems in these areas face significant management and regulatory pressures. This study provides an integrated framework for systematically identifying cropland destabilisation risks in arid oasis regions and offers theoretical and decision-making support for the implementation of targeted regulatory measures and sustainable cropland protection strategies.