Abstract: In order to achieve maximum effective heat transfer area and heat transfer coefficient, some important parameters of a new cracking tower with multiple hollow disks were optimized on the basis of heat-mass transfer model developed in Part（Ⅰ）, including the area overlapping ratio, rotating speed of axis, plow-setting coefficient, number and setting angle of plows, distance between plows.It was shown that the area-overlapping ratio was better in the interval of 0 to ξ_c.A higher rotating speed of axis was preferred provided that the quality of pyrolysis products was not affected.Multiple plows system was recommended in the design of a new cracking tower for waste tires.The distance between plows was optimal when the critical capacity values of all annular granular heaps were equal.The setting angle of 45° was helpful to decrease the drag force acting on plow and enhance mixing of granular heaps.