Film thickness uniformity in a magnetron sputtering system is one of the key indicators. The effects of magnetic field intensity, distance between target and substrate and gas pressure on the thickness uniformity of Si₃N₄ and SiO₂ films are analyzed. The plasma density is analyzed by using Langmuir probe, and the longitudinal uniformity is adjusted by binary gradient inflation mode. By loading sine half-wave voltage to the target and using MATLAB software to determine the amplitude and phase parameters, so as to adjust the uniformity of the transverse. The experiment results show that for the Si₃N₄ film, the transverse uniformity is ±1.27%, ±0.62%, and ±1.33% respectively at the top, middle, and bottom, and the longitudinal uniformity is ±0.33%. For the SiO₂ film, the transverse uniformity is ±1.12%, ±0.42%, and ±1.23% respectively at the top, middle, and bottom, and the longitudinal uniformity is ±0.25%.