Vibration during disk brake process will generate brake noise and uneven contacting between brake pad and brake disk, so it is important for analysis the whole disk brake system’s performance to research the vibration characteristics of the brake disk. Based on the Japan Chiba Prefecture type 0 suspended monorail vehicle, the solid model of brake disk and brake pad was established, and a finite element analysis of free modal and constrained modal was taken out, and the preceding eight natural frequencies was obtained. Based above, the vibration characteristic of both brake disk and brake pad was analyzed, which provided the theoretical basis of brake system’s optimal design.