1. A disc brake, comprising a brake disc, a machine body movably connected to a frame, two brake shoes, one of which is mounted onto the machine body and the other is positioned at one side of the brake disc; a drive device and a compensation device; wherein the brake shoe positioned at one side of the brake disc is mounted onto one side of an energizing inclined board; a first self-energizing inclined surface on the other side of the energizing inclined board is abutted against a second self-energizing inclined surface on one side of a control inclined board, such that the energizing board is driven by the control inclined board; wherein the control inclined board further comprises a first control inclined surface and a second control inclined surface on the other side opposite to the second self-energizing inclined surface of the control inclined board; wherein the compensation device comprises a compensation board having a first compensation inclined surface and a second compensation inclined surface; wherein the first control inclined surface is abutted against the first compensation inclined surface and the second control inclined surface is abutted against the second compensation inclined surface; the control inclined board is further abutted against a retaining device; the retaining device is connected with a control device.