Harvest bales in the field, including process of collecting， transportation, loading and stacking bale all need to consume a lot of time and labor, thus to improve the bale harvest efficient, it was needed to design collecting wagon of rectangular bale. Its structure was mainly composed of traction device, feeding device, bale thruster, unloading device, collection tank and the electrohydraulic control system. Collecting wagon of rectangular bale was hooked up to the rear side of compression chamber of rectangular bale baler, bales were arranged to collect according to certain rules, and finally unloaded the bale group on the ground. When collection jobs of collecting wagon of rectangular bale were affected by terrain condition, bale shape, bale density and other factors, sometimes tilt of bale would happen in the process of feeding, which seriously affected the work efficiency and stability. According to problems that working stability was seriously impacted by bale tilt in the feeding process of collecting wagon of rectangular bale, ARIZ was used to analyze feeding device of critical component of collecting wagon of rectangular bale, and determine the cause of the problem. Through analyzing the system components function, it indicated that the main reason leading to bale tilt was insufficient feeding device to bale guidance function. Aiming at the problems existing in the technical system, technical contradictions, object-field analysis and other methods were used to do systematic analysis; totally 40 innovative principles, separation principle, knowledge base query and 76 standard solutions of the TRIZ were applied, and a series of innovative design was formed. By using Pro/Innovator software, the work efficiency, equipment reliability, production costs and complexity of equipment were comprehensively evaluated for the new solutions to get the optimal solution. Finally, through test of the improved machine, results showed that the improved machine had advantages of high collecting efficiency and good working stability. Bale group neat rate was 100%, and the main performance indicators all met the requirements of relevant standards. Therefore, the results can provide reference for the relevant field of ARIZ innovative design products.