Full-disc multi-disc brake with relatively fixed disc positions

The invention discloses a full-disc multi-disc brake with relatively fixed disc positions, which comprises a motor frame, a brake shell, a piston shell, an end cover and a motor shaft coaxially and rotatably mounted on the motor frame, a plurality of friction plates which slide in the axial direction and are fixedly arranged in the circumferential direction are arranged on the shaft sleeve, and a plurality of brake plates which slide in the axial direction and are fixedly arranged in the circumferential direction are coaxially arranged in the brake shell; the outer diameter of the friction plate is greater than the inner diameter of the brake plate; limiting mechanisms suitable for limiting axial displacement of the brake pads are arranged between the brake shell and the brake pads, and return mechanisms are arranged between the adjacent friction pads and between the friction pads and the first check blocks. Reliable disc gaps can be guaranteed, the disc attaching probability is greatly reduced, the service l