In order to explore the nitrogen reducing effect of synergists on dryland wheat in Sichuan, the following 9 treatments were set up in this study: blank control (CK0); Conventional nitrogen application without topdressing (CK1, nitrogen application amount 187.5 kg/hm²); The ratio of basal dressing to topdressing under conventional nitrogen application rate is 6∶4 (CK2, nitrogen application rate is 187.5 kg/hm²); Synergistic auxiliary mixed with conventional compound fertilizer, reducing nitrogen by 20% (jf—20%) and 30% (jf—30%); Synergistic auxiliary chelating urea formaldehyde reduces nitrogen by 20% (jn—20%), 30% (jn—30%) and 40% (jn—40%); Synergistic auxiliary chelated urea formaldehyde fertilizer + lecithin organic fertilizer 3 000 kg/hm² reduced nitrogen by 27% (jny—27%); The dynamics of soil nitrogen, wheat chlorophyll content, leaf area index, growth rate, nitrogen accumulation and transport, yield and its composition, and nitrogen utilization efficiency were analyzed and measured under different treatments. The results showed that each treatment of jf, jn and jny model significantly reduced the content of ammonia nitrogen and nitrate nitrogen in soil at flowering and mature stages, which were 6.8%~9.8% and 8.7%~14.5% lower than that of CK1 at flowering stage, and 14.9%~20.8% and 15.9%~20.0% lower at mature stage, respectively. At 30 days after anthesis, the leaf area index of jn—20% and jny—27% was the highest, 5.3% and 5.8% higher than that of CK1 and CK2, respectively. The leaf area index of jn—20% and jny—27% was 5.83% and 5.24% higher than that of CK1; Each treatment of jf, jn and jny mode significantly increased the post anthesis nitrogen accumulation compared with CK1 and CK2, with the amplitude of 33.7%~73.1% and 29.8%~68.0% respectively, and the post anthesis nitrogen transport increased by 116.1%~217.8% and 107.1%~204.0% respectively. The growth rate of each treatment of jf, jn and jny in flowering maturity stage was higher than that of CK1, and the range was 13.2%~33.8%. Moreover, wheat yield will not decrease after nitrogen fertilizer reduction and synergist application. The yield increase of jf—20%, jn—20% and jny—27% was 0.2%~2.9%, and the yield of jn—20% and jny—27% treatment was the highest, 2.6% and 2.9% higher than that of CK1, however, there is no significant difference with CK1 and CK2. jn, jf and jny modes significantly improved nitrogen utilization efficiency and partial productivity of nitrogen fertilizer, which were 6.7%~24.0% and 10.3%~25.8% higher than CK1 respectively. According to the research, the synergists can improve the fertilizer utilization rate by promoting nutrient absorption and reducing nitrogen residues in the soil, so as to reduce nitrogen without reducing production. The application of synergists to mix fertilizer and synergists to chelate urea formaldehyde can reduce nitrogen by 20%, and synergists to chelate urea formaldehyde with lecithin organic fertilizer 3 000 kg/hm² can reduce nitrogen by 27%.