Abstract: 【Objective】 To study the effects of nitrogen fertilizer ratio and planting spacing on cotton growth and yield under the condition of one film and three rows, and to select the best combination. 【Method】 Taking Xinluzhong 88 as the tested variety, the split-zone test design was adopted, with three nitrogen fertilizer topdressing strategies in the main zone and three plant spacing of 10, 8 and 6 cm in the sub-zone.Effects of different treatments on the growth and development of cotton, the spatiotemporal distribution of cotton bolls, the shedding rate of buds and bolls, yield and fiber quality were analyzed. 【Results】 The number of bolls in the treatment of nitrogen fertilizer application was more N₂, and the number of bolls was 8.7% -23.3%, 8.82% -36.5% higher than that of N₁ and N₃.The spatiotemporal distribution of cotton bolls was more ideal, and the rate of boll shedding was low, which increased yield.The quality of treated fiber was significantly better than the other two treatments.Combining the yield components such as the number of harvested plants, the number of bolls per plant, and the weight of single bolls, the treatment with N₂ and plant spacing of 8 cm (D₂) with nitrogen fertilizer had the highest yield, and the yield of lint cotton was 3,025.65 kg/hm². 【Conclusion】 Under the one-film three-row mode, N₂D₂ can achieve high yield when nitrogen fertilizer is applied and the plant spacing is 8 cm, which is suitable for popularization and application in production.