[Objective] To analyze the spatiotemporal variations and mutual interactions between climate and vegetation in the Three-North Region, providing new evidence for understanding the coupling mechanisms between climate and vegetation in arid and semi-arid zones. This holds significant implications for ecological initiatives such as the Three-North Shelterbelt Project. [Methods] Using northwestern, northern, and northeastern China as the study area, the Sen+ M-K trend analysis, coefficient of variation, and correlation coefficient methods were applied to examine the precipitable water vapor (PWV), wind speed, and normalized difference vegetation index (NDVI) in the Three-North Region from 1982 to 2024. [Results] ① Annual averages of PWV, wind speed, and NDVI all exhibited increasing trends. with areas of extremely significant PWV increase (28.49%) concentrated in high-altitude regions such as the Qinghai Plateau. Regions with significant wind speed changes (combined increase/decrease of 12.68%) were primarily distributed in arid basin areas. Areas of extremely significant NDVI increase (51.65%) were concentrated in ecological project implementation zones (e.g., the Loess Plateau), while regions like the Lesser Khingan Mountains exhibited significant degradation trends (13.83%); ② The coefficients of variation for the three variables were 0.05, 0.03, and 0.07 respectively; ③ PWV and NDVI exhibited positive correlation in 79.75% of interannual and 84.17% of inter-monthly scales, with a monthly correlation coefficient of 0.60, indicating a strong relationship. The annual correlation between wind speed and NDVI exhibits regional differentiation: positive correlation (63.50%) occurs at the periphery of the monsoon zone, while negative correlation (36.50%) prevails in the arid northwest. [Conclusion] From 1982 to 2024, PWV, wind speed, and NDVI in the Three-North Region generally increased in tandem, signifying significant improvement in regional climate and ecological environment. Their spatiotemporal correlations are jointly regulated by topography, climate, and human activities, exhibiting pronounced regional variations.