In order to solve the problem that corn straw bales tend to fall apart during collection and handling, we started from the analysis of the forces on corn straw bales and studied the changes of the load during bale resting, shifting, and deformation, as well as the factors affecting the stability of bales. The optimum combination of bale density of 175 kg/m ³, straw bale length of 88 cm, number of bale cords of 3, and bale drop resistance of 93.5% was determined through response surface analysis. The bale stability fully meets the production requirements and provides theoretical guidance for the research of the square straw bale baler.