The calculation method of the static carrying curve of the double-row different-diameter ball slewing bearing was proposed. The relationship between the internal maximum rolling element load of each row and the external load combination of the slewing bearing was established by using the deformation compatibility conditions and the force equilibrium conditions. Using the rolling element load distribution range parameter of the main raceway and the auxiliary raceway of the double-row different-diameter ball slewing bearing respectively as input invariable, the corresponding external load combinations of axial load and tilting moment load of the slewing bearing were obtained. These external load combinations were plotted in the coordinate system to obtain the static carrying curve of the slewing bearing. The obtained static carrying curve was compared with that calculated by the finite element method for the verification purpose. Finally, influence laws of the detailed design parameters, such as raceway groove radius coefficient, raceway contact angle and rolling element diameter on the carrying capacity of the double-row different-diameter ball slewing bearing were analyzed by using the carrying curves. The results show that decreasing of raceway groove radius coefficient, increasing of rolling element diameter or increasing of raceway contact angle appropriately is advantageous for enhancing the carrying capacity of the double-row different-diameter ball slewing bearing.