In view of the fact that the current collection and processing of cotton stalks are done manually, which is labor-intensive, inefficient and unable to meet the market demand,the work aims to design an automatic baling device for cotton stalks with the common JX013 cotton stalk as the research object, By studying the parameters of cotton stalk, the pre-processing mechanism, compression mechanism and baling mechanism was designed to complete the automatic baling of cotton stalk. UG was used to set up the 3D model of device, and perform virtual assembly and simulation. The results of the device can successfully complete a series of work of cotton straw pre-processing, compression and baling. Finally, the cotton stalks are compressed into square straw bales, with a compression density of 65 kg/m3, a baling efficiency of 200 bales/h and a baling rate of 99%. The structure of the machine is reasonable. Under the premise of ensuring the bundling rate, the work efficiency of cotton stalk bundling is greatly improved, and the labor intensity of workers is reduced.