Aiming to address the issues of uneven crushing and straw drop during the cotton stalk fragmentation and returning process in Xinjiang, the design of a secondary wind-assisted cotton stalk crushing and returning device was optimized. The device employed a dual-helix crushing blade set and a wind-assisted conveying blade set for collaborative operation, integrating a diversion air duct to achieve primary crushing and secondary conveying of stalks. The structural configuration and parameters of key components were determined through theoretical analysis. To investigate the influence of operational parameters on the internal flow field during the crushing and conveying process, CFD simulations were conducted to analyze the effects of crushing blade shaft speed, conveying blade shaft speed, and the number of wind-assisted blades. A three-factor three-level orthogonal experiment was performed with crushing blade shaft speed, ground clearance, and conveying blade shaft speed as experimental variables, and stalk drop rate and crushing qualification rate as evaluation metrics. Parameter optimization yielded the optimal combination: crushing blade shaft speed of 2490r/min, ground clearance of 77mm, and conveying blade shaft speed of 2870r/min. Field validation tests under these conditions resulted in a stalk drop rate of 3.41% and a crushing qualification rate of 97.85%, with relative errors between experimental and theoretical values below 5%, meeting industry standards. This research can provide technical support for enhancing the efficiency of cotton stalk returning equipment.