Drum brake and vehicle

The utility model provides a drum brake and a vehicle. The drum brake includes: a brake bottom plate including a first support portion and a second support portion; the supporting pin comprises a limiting part, an inserting part and a locking part which are sequentially arranged, the inserting part is inserted into the first supporting part and the second supporting part, the limiting part is located on the side, away from the second supporting part, of the first supporting part and abuts against the first supporting part, and the locking part is located on the side, away from the first supporting part, of the second supporting part; the inserting part is inserted into the brake shoe, the brake shoe is rotationally connected with the inserting part, and the brake shoe is located between the first supporting part and the second supporting part; and the locking mechanism is mounted on the locking part so as to limit the axial displacement of the inserting part. Under the condition that the brake shoe of the dru