In China, food security has long held a critical strategic position. Conducting research on the interconnections between People-Land-Food (P-L-F) is of significant importance for promoting the efficient use of resources and ensuring national food security. In this research, we utilize the entropy weighting technique coupled with an integrated adaptability assessment framework to gauge the composite development and adaptability indices of the P-L-F nexus in Xinjiang over the two-decade period from 2000 to 2020. Furthermore, we apply a barrier analysis model to identify impediments to the harmonious and adaptive progression of this intricate system. Results indicate the following: (1) From 2000 to 2020, Xinjiang's P-L-F system grew at an average annual rate of 1.39%, with people, land, and food subsystems increasing by 0.32%, 1.99%, and 1.9%, respectively. (2) Regional adaptability varied significantly-southern Xinjiang improved over time, while the north remained higher overall; dual subsystems showed steady enhancement. (3) The people subsystem's barrier intensity increasingly outpaced that of the food subsystem, highlighting that the dynamics between people and land emerged as the primary constraints on the harmonious and adaptive evolution of the P-L-F nexus. The study offers insights into P-L-F coordination and sustainable development in arid regions.