A field split plot experiment was conducted in the southern Xinjiang region with Xindao 36 as the material, nitrogen fertilizer level(N) as the main plot and planting density(D) as the sub plot. The results showed that with the increase of nitrogen application rate, the length and bending moment of the first and second internodes, the plant height and center of gravity height significantly increased. The bending resistance first increased and then decreased, with the highest in N2 treatment(240 kg N/hm²). Reasonable close planting can control the individual development and reduce the internode length, bending moment, plant height and center of gravity height. The lodging index of stem is affected by the above indexes. When the nitrogen application rate is 240 kg/hm², combined with planting density of 208 300~277 800 holes/hm², the lodging resistance is better. The contribution of dry matter accumulation to grains after flowering accounted for 51.69%~76.14%, which was the main source of dry matter accumulation in grains. Proper application of nitrogen fertilizer could improve the dry matter accumulation and accumulation rate after flowering. Excessive fertilization will increase the accumulation of dry matter before flowering, which is mainly used for the growth of vegetative organs and is not conducive to transportation to grains. Moderate dense planting is beneficial for increasing the accumulation of dry matter after flowering, with D4 treatment(277 800 holes/hm²) increased by 18.06%~30.22% compared to other treatments, and also promoting the transport of dry matter to grains. In general, when the nitrogen application rate is 240 kg/hm² and the density is 277 800 holes/hm², the dry matter proportion and dry matter distribution of the aboveground parts are significantly improved, and no lodging occurs, which is conducive to the increase of yield.