Brake, brake clearance self-adjusting device and vehicle

The utility model provides a brake, a brake clearance self-adjusting device and an automobile, and relates to the technical field of automobile braking. A brake comprises a brake drum, a first brake shoe, a second brake shoe, a return elastic piece and a brake clearance self-adjusting device. According to the brake clearance self-adjusting device, the movement clearance is formed between the pull rod and the sliding block and matched with the distance between the brake shoe and the brake drum, so that in the braking process, the pull rod synchronously moves along with the brake shoe, and a tiny excessive clearance generated at any time is compensated through real-time fine adjustment. The device is simple in structure, low in manufacturing cost, small in occupied space and capable of compensating the excessive braking clearance in real time. And the structure facilitates the disassembly of the brake, the brake clearance can be quickly enlarged during installation, and the installation of the brake drum is fac