Planting density affects how much nitrogen is taken up and used by late-sown winter wheat. Higher planting densities led to more nitrogen stored in the plant's vegetative parts being moved to the grain. Late sowing increased nitrogen accumulation per stem and nitrogen intake efficiency, but decreased nitrogen use efficiency and grain yield compared to traditional early sowing. The middle planting density showed higher nitrogen metabolism enzyme activity, nitrogen use efficiency, and grain yield in early sowing, while the high density was more effective in late sowing. For the winter wheat variety Lankao Aizao 8, planting densities of 225×104 and 300×104 plants/hm2 are recommended for late sowing to balance grain yield and efficient nitrogen use.