Abstract: 【Objective】 To explore the regulation effect of drip irrigation-chemical control collaborative management on cotton and the cotton planting management measures to further improve the efficiency of cotton planting. 【Methods】 The new machine-picked cotton variety Huiyuan 720 was used as the test material, and the two-factor split-plot design was adopted. The drip treatment was set as the main area, and three levels of 6,000 m³/hm² ( W₁ ), 4,500 m³/hm² ( W₂ ) and 3,000 m³/hm² ( W₃ ) were set. The dose of mepiquat chloride (DPC) in the topping stage ( July 4 ) was set as the sub-area, and 90 g/hm² ( D₁ ) was set. 180 g/hm² (D₂) ; 270 g/hm² (D₃), and artificial topping as control CK. Then the canopy structure, dry matter accumulation, yield and quality of each treatment were measured. 【Results】 (1) The increase of leaf area index of whole plant in W₁ and W₂ treatments was significantly higher than that in W₃ treatment by 32.42% and 18.96%. The canopy openness in W₃CK treatment was significantly higher than those in W₁CK and W₂CK treatments by 47.83% and 17.24%. Light transmittance increased with decreasing drip water and increasing DPC dose. Reflectivity decreased with decreasing drip water and increasing DPC dose. (2) The total dry matter accumulation exhibited the sequence W₁>W₂>W₃; D₁>D₂>D₃>CK. The proportion of dry matter in reproductive organs in W₃CK, W₂D₂ treatments was significantly higher than that in W₁D₁ treatment by 16.67% and 9.52%. The seed cotton yield and lint yield of W₂D₂ treatment were notably high. 【Conclusion】 In summary, under the experimental conditions, employing a drip volume of 4,500 m³/hm² alongside 180 g/hm² of DPC proves effective in reducing planting costs while also regulating the accumulation and distribution of dry matter.