A method for changing stiffness and preventing folding and cracking of a conical spring, wherein the conical spring comprises an inner conical body, a rubber body and an outer conical body, wherein the rubber body encircles the periphery of the inner conical body, the outer conical body encircles the periphery of the rubber body, the rubber body, the inner conical body and the outer conical body form a conical rubber metal spring together, wherein an upper rubber profile of the rubber body and a lower rubber profile of the rubber body of the conical spring adopt a multi-segment structural form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure, and the lower rubber profile of the rubber body is of a multi-section upslope structure; for the conical spring, the extent of stiffness change and the position of stiffness change of the conical spring are adjusted by adjusting the shape, slope and length of each section in the multi-section downslope structure of the upper rubber profile of the rubber body and the multi-section upslope structure of the lower rubber profile of the rubber body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections, wherein the inner conical body extends to the outer side to form an annular inner conical body lug boss such that when rubber body moves downwards under large vertical load, at this moment the lower end of the rubber body is fitted with the inner conical body lug boss, the method being characterized in that the upper surface of the lug boss is of a multi-section structure, every two sections adopt an arc section for transition, the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss and the opening angle of the inner side of the outer conical body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections. wherein the conical spring comprises an inner conical body, a rubber body and an outer conical body, wherein the rubber body encircles the periphery of the inner conical body, the outer conical body encircles the periphery of the rubber body, the rubber body, the inner conical body and the outer conical body form a conical rubber metal spring together, wherein an upper rubber profile of the rubber body and a lower rubber profile of the rubber body of the conical spring adopt a multi-segment structural form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure, and the lower rubber profile of the rubber body is of a multi-section upslope structure; for the conical spring, the extent of stiffness change and the position of stiffness change of the conical spring are adjusted by adjusting the shape, slope and length of each section in the multi-section downslope structure of the upper rubber profile of the rubber body and the multi-section upslope structure of the lower rubber profile of the rubber body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections, wherein the inner conical body extends to the outer side to form an annular inner conical body lug boss such that when rubber body moves downwards under large vertical load, at this moment the lower end of the rubber body is fitted with the inner conical body lug boss, the method being characterized in that the upper surface of the lug boss is of a multi-section structure, every two sections adopt an arc section for transition, the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss and the opening angle of the inner side of the outer conical body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.