Abstract: 【Objective】 This study further carried out the research on the impact of biochar single application and combined application of nitrogen fertilizer on the population structure, photosynthetic characteristics and yield of spring wheat in irrigation areas, aiming to provide scientific basis for the rational use of biochar and fertilizer. 【Methods】 The experiment adopted a randomized block design, set up 2 nitrogen fertilizer application levels (0, 150 kg/hm²) and 4 levels of biomass charcoal (0, 10, 20, 30 t/hm²) for research. After that, the population structure, photosynthetic characteristics and yield of Xinchun 46 wheat were analyzed in 2020. 【Results】 The results showed that under B₂N₁ treatment, nitrogen fertilizer reduction (150 kg/hm²), compared to medium biomass charcoal (20 t/hm²) under the combined application, the population structure, leaf area index, leaf SPAD value, net photosynthetic rate, and yield of spring wheat all reached the optimal level, increased by 15.04% to 32.98%, 3.67% to 89.82%, 5.63% to 11.46%, 17.95% to 81.68%, and 29.73% compared to the control, respectively. Compared with the control, the single application of biochar and the combination of biochar and nitrogen fertilizer increased spring wheat yield by 7.52% to 29.73%. 【Conclusion】 Nitrogen fertilizer is reduced by 150 kg/hm² and applied in combination with 20 t/hm²(B₂N₁) biochar has the best effect in increasing production.