In order to determine the optimal application amount of biochar on maize cultivation in meadow soil in semi-arid area, a field plot experiment were carried out to study the effects of different amounts of biochar（0 t/ha,10 t/ha, 20 t/ha, 40 t/ha, 80 t/ha） on soil nutrient, soil enzyme activity and crop yields. Results showed that biochar addition increased the content of soil organic carbon, total nitrogen and available potassium, which were positively correlated with the application rate of biochar. The treatment of 80 t/ha significantly improved the contents of soil available phosphorus, and the soil enzymes activity of urease, alkaline phosphatase, sucrase and catalase, and the effect lasted longer. The application of biochar at different dosage promoted the maize yield. The treatment of 10 t/ha,20 t/ha, 40 t/ha, 80 t/ha increased by 1.16%, 9.97%, 28.53% and 42.13% in comparison with control, respectively.Therefore, the application of biochar improved soil nutrient status, the soil enzyme activity, and promoted crop yields. With the increase of the application amount of biochar in the range of the 0-80 t/ha, its effect was more significant for maize cultivation in meadow soil in semi-arid area.