The invention discloses a silicon rod squarer and a silicon rod squaring method. The silicon rod squarer comprises a machine base, a silicon rod supporting device and a silicon rod cutting device, wherein the silicon rod supporting device and the silicon rod cutting device are arranged on the machine base and move relatively. The silicon rod supporting device is used for supporting a to-be-cut silicon rod and ensures that the to-be-cut silicon rod is vertically arranged, the silicon rod cutting device is used for conducting length-direction side face cutting of the to-be-cut silicon rod on the to-be-cut silicon rod supported by the silicon rod supporting device so as to obtain an axial section through cutting, and therefore the squaring work of the to-be-cut silicon rod is completed.