The invention discloses a controlling method and equipment for the broken rate of biennial roots. The controlling method and equipment for the broken rate monitor the frequency of several external excitation sources in real time, and adjust the frequency of each vibration absorber arranged on a cutter in real time according to the frequency of each external excitation source to make the frequency of each vibration absorber equal to the maximum frequency of the corresponding external excitation, namely absorbing forced vibration signals through the cutter, to reduce the cutter disc vibration amplitude of the cutter and therefore the controlling method and equipment for the broken rate of biennial roots reduce the broken rate of the biennial root of sugarcane, improve the germination rate of the next year, reduce the production cost, save the resources, and further are conducive to the promotion and usage of the equipment.