[Objective] To investigate the effects of magnetic field intensity on the movement patterns of soil water and salt under drip irrigation with different water sources, and to determine the optimal magnetic field strength. [Methods] A field experiment was conducted from May 2023 to October 2024 in Dalate Banner. The experiment included two types of irrigation water sources（Yellow River water [F] and slightly saline water [B]） and four levels of magnetic field intensity（M）（0.5 T, 0.3 T, 0.1 T and 0 T）. The study examined the mechanisms by which different treatments affect soil water and salt dynamics, salt leaching and ion migration. [Results] Magnetized water drip irrigation significantly increased the soil volumetric water content in the crop root zone, promoted salt leaching, alleviated water-salt stress in the root zone, and effectively reduced the mass fractions of Cl^-, SO₄^2-and Na+ in the soil. Under different magnetic intensities, FM and BM treatments showed significant differences. When the magnetic field intensity was 0.3 T, the root-zone soil volumetric water content of FM3 and BM3 treatments increased by 3.03%-3.35% and 1.58%-3.16%, respectively, and the desalination rates increased by 8.83%-14.56% and 7.07%-13.62%, respectively, compared with FM0 and BM0. These treatments also achieved better Cl^-and Na⁺ removal, with FM3 showing removal rates of 19.17%-31.67% and 33.95%-42.91%, and BM3 achieving 5.20%-21.03% and 20.41%-26.02%, respectively. When the magnetic field intensity was 0.5 T, SO₄^2-removal was most effective, with FM5 and BM5 reaching 30.97%-35.22% and 25.81%-26.02%, respectively. In addition, magnetized water drip irrigation effectively reduced areas affected by soil water-salt stress and showed potential in improving the soil water-salt environment. Fitting analysis indicated that a magnetic field range of 0.29-0.38 T was optimal for improving the root-zone water-salt environment. Drip irrigation with magnetized water using both irrigation sources can enhance root-zone soil moisture and promote salt leaching. [Conclusion] Magnetized water drip irrigation significantly improves the root-zone soil water-salt environment. A magnetic field strength of 0.3-0.4 T is optimal for highly saline-alkali farmland in the Yellow River irrigation area. These findings provide theoretical support for improving saline-alkali land and the efficient utilization of water resources in the Yellow River irrigation area.