To provide a theoretical reference for scientifically applying biochar and improving the utilization of nitrogen fertilizers,33 publicly published documents were collected,and 170 sets of nitrogen fertilizer utilization data including biochar combined with chemical fertilizer (NPK+BC) and single chemical fertilizer (NPK) treatment were established,and integrated analysis (Meta-analysis) to study the differences in nitrogen use efficiency in various regions under NPK and NPK+BC treatments. Quantify the impacts of biochar on the nitrogen use efficiency (NUE) of crops from various aspects:different areas,soil nutrients,nitrogen fertilizer dosage,biochar characteristics and application rate,crop types. In general,the application of biochar could increase the NUE of crops by about 4.76%. Among these regions,the effect of biochar promotion in the southern region was the most pronounced,increasing by about 11.73%. Soil fertility could affect the effects of biochar on NUE. The application of biochar had the best effect on the improvement of NUE of corps in the southern regions with low pH,organic matter and available nitrogen content,while the effect was relatively low in the northeast regions with high organic matter and pH. When the nitrogen fertilizer application rate was less than 120 kg/hm2,the synergistic effect of biochar was the most evident,and the NUE was increased by 10.73%. The nitrogen utilization rate was higher in grain crops than in commercial crops,and it was increased by 5.71%. The amount of biochar that is applied should be controlled below 1%,and the NUE should be increased by 3.43%. The improvement effect of biochar made from wood materials was the most obvious,and the NUE was increased by 7.99%. When the nitrogen content of biochar exceeded 2%,the NUE could be increased by 19.43%. When the pH of biochar was 9-10,the NUE could be increased by 5.01%.