With intensifying climate change and anthropogenic activities, the spatial distribution and productivity of global farmland are undergoing significant shifts. Comprehensive understanding of these changes across different altitudinal gradients remains limited. This study aims to analyze regions of significant farmland change from 1981 to 2015, focusing on how climate change and anthropogenic activities influence these changes across different altitudes. The study utilizes Ordinary Least Squares regression and Mann-Kendall tests to identify significant farmland changes. Residual analysis is used to pinpoint areas where climate change is the predominant factor, while partial correlation analysis explores the climatic factors influencing farmland across various altitudes. Significant changes in global farmland are primarily concentrated within the 0-200 m altitude range, with significantly greening areas outweighing browning areas across most months and altitudinal ranges. Below 1200 m, anthropogenic activities have a greater impact on farmland changes, whereas above 1200 m, climate change exerts a more pronounced influence. Specific climatic factors such as temperature, precipitation, sunshine duration, and soil moisture show significant variations in their effects on farmland changes across different altitudes and months. This study offers a scientific basis for developing agricultural management and climate adaptation policies.