In order to explore the response of irrigated silt soil to different tillage methods and different biochar additions，the nutrient content and enzyme activity were measured，in order to provide a scientific basis for selecting suitable tillage methods and fertilization systems in the Hexi Corridor region. An 8-year field experiment was conducted with four tillage methods(N:no-tillage，M:less-tillage，F:autumn ploughing，S:subsoiling )and three biochar application rates(B1:2.5 t/hm²，B2:5.0 t/hm²，B3:7.5 t/hm²)in maize field，and without tillage and no application of biochar was the control(CK). The results showed that:(1)In the 0-20 cm soil layer，compared with CK，different treatments significantly increased soil organic carbon，available nutrients and enzyme activity(P<0.05). Soil organic carbon，available nutrients and soil enzyme activity increased with the increase of biochar application rate under different tillage methods.(2)In 20-40 cm soil layer，compared with CK，different treatments increased soil organic carbon，available nutrients and enzyme activity，but there was no significant difference among treatments(P>0.05).(3)Different treatments could increase maize yield，but there was no significant difference among treatments(P>0.05). Compared with CK treatment，the yield-increasing effect of each biochar treatment was between 0.07% and 21.30%，and the yield of FB3 treatment was the highest，which was significantly higher than that of other treatments(P<0.05).(4)Correlation analysis showed that there was a significant positive correlation between soil nutrients and soil enzyme activities(P<0.05). Subsoiling tillage combined with biochar addition could effectively improve soil nutrients and enzyme activity，which was conducive to crop growth，and it was a more suitable tillage method in this area. Biochar above 7.5 t/hm² could be applied as an important additive for the improvement of irrigated silt soil.