Soybean film mulching has shown promise in maintaining consistent and high yields in semi‐arid regions. However, the specific impacts of full‐film and semi‐film mulching on soybean growth, root nodule traits and grain yield are poorly understood. This 2‐year study (2021–2022) investigates the effects of full‐film and semi‐film mulching on soil moisture, soybean growth and yield. Our findings revealed that semi‐film mulching increased soybean yield by 18.12% compared to full‐film mulching, averaged across 2 years. Furthermore, the semi‐film treatment significantly enhanced biological nitrogen fixation ability, increasing root nodule numbers by 24.81%–33.43%, compared to full‐film mulching. This improvement also positively affected soybean quality, with crude protein content increasing by 5.89% in 2021 and 4.14% in 2022 compared to full‐filming. Moreover, semi‐film mulching helped maintain soil moisture and temperature during later soybean growth stages. There findings suggest that semi‐film mulching is a viable agricultural strategy for soybean cultivation in semi‐arid regions, improving soybean quality and efficiency while promoting environmental sustainability.