Field experiment was set up in Nong’an County, Jilin Province from 2017 to 2019. Field double factor split design was employed, with two straw treatments in main plots, which were straw returning J (12 000 kg/hm²) and no straw returning (W), and the sub-plots were magnesium fertilizer M3 (10 kg/hm²), no magnesium fertilizer M0, and the treatments included JM3 (straw + magnesium fertilizer), JM0 (straw + no magnesium fertilizer), WM3 (no straw + magnesium fertilizer) and WM0 (no magnesium fertilizer + no straw). The results showed that during the growth period of maize, the content of exchangeable magnesium in the soil gradually decreased. At the mature stage, the content of soil exchangeable magnesium in JM3 treatment was 6.59%, 8.47% and 14.09% higher than that in WM3, JM0 and WM0 treatment, respectively. The application of magnesium fertilizer could promote the magnesium absorption in maize plants, and straw returning to the field combined with magnesium fertilizer application could further increase the uptake of magnesium in maize. The average magnesium accumulation in the WM3 treatment was 12.30% higher than that in WM0 treatment. The magnesium accumulation in JM3 treatment was 9.79%, 15.99% and 23.28% higher than that in WM3, JM0 and WM0 treatments, respectively. The accumulation of dry matter in maize increased continuously during the growth period. Applying magnesium fertilizer could improve the production of dry matter and the yield of spring maize. At the maturity growth stage, the dry matter accumulation and yield of maize in WM3 treatment was 5.30% and 4.38% higher than that in WM0 treatment. The dry matter accumulation and yield of maize in JM3 treatment was 11.50% and 5.52% greater than that in WM0 treatment. In conclusion, the application of magnesium fertilizer could significantly improve the content of exchange able magnesium in soil, promote the absorption of magnesium nutrients in spring maize plants, increase the dry matter accumulation and spring maize yield. Straw returning to the field with applying magnesium fertilizer could not only improve the content of soil exchangeable magnesium, maintain the continuous and effective supply of soil magnesium in the whole growth period of maize, but also further promote the absorption of magnesium nutrients by spring maize plants, increase the dry matter accumulation and yield of spring maize.