Abstract: 【Objective】 To screen out the most suitable planting density suitable for planting with 76 cm machine pick up cotton equal row spacing. 【Methods】 From April to October 2020, 76 cm equal row spacing plastic film was used for planting, with 9×10⁴ plants/hm² (A) and 12×10⁴ plants field trials were conducted at five planting densities of /hm² (B), 15×10⁴ plants/hm² (C), 18×10⁴ plants/hm² (D), and 21×10⁴ plants/hm² (E). Inclination angle (MTA), canopy opening (DIFN), light interception rate, canopy temperature, humidity, yield and other indicators were used to study the effects of different planting densities on cotton canopy structure, canopy temperature and humidity and yield. 【Results】 The LAI and leaf inclination angle of each treatment increased with the increase of planting density, which always showed E>D>C>B>A, and the canopy opening basically showed A>B>C>D> E; The light interception rate of each treatment basically showed a "V"-shaped variation trend in space, and the higher the density, the lower the average temperature and the higher the average humidity in the canopy. When the treatment level was 15×10⁴ plants/hm², the number of bolls per plant and the weight of single bolls were significantly increased compared with the control, and the yield of seed cotton was 4,849.96 kg/hm². The yields were increased by 41.94%, 24.20%, 4.72% and 15.20% respectively compared with other treatments. 【Conclusion】 Comprehensively considering, in this experiment, the density of 15×10⁴ plants/hm² can obtain a better cotton canopy structure, which is beneficial to the canopy light distribution and obtains higher yield.