A buffer gear, comprising: a buffer assembly; a connection assembly, the connection assembly comprising: a connection body, the connection body has: a first connection part, the first connection part is mutually and horizontally rotatably connected with the buffer assembly, and the first connection part and the buffer assembly have a first rotation center; a second connection part, the second connection part has a connection surface, the second connection part is connected with a train body through the connection surface, and the first rotation center is located at a first side of the connection surface towards the train body; a bearing assembly, located below the buffer assembly and providing support for the buffer assembly; the bearing assembly is in mutual contact with the buffer assembly, the bearing assembly is mutually and horizontally rotatably connected with the connection assembly, the bearing assembly and the connection assembly have a second rotation center, the second rotation center is located at a second side of the connection surface towards the buffer assembly; and a self-adaption assembly, the bearing assembly is connected with the buffer assembly by the self-adaption assembly. a buffer assembly; a connection assembly, the connection assembly comprising: a connection body, the connection body has: a first connection part, the first connection part is mutually and horizontally rotatably connected with the buffer assembly, and the first connection part and the buffer assembly have a first rotation center; a second connection part, the second connection part has a connection surface, the second connection part is connected with a train body through the connection surface, and the first rotation center is located at a first side of the connection surface towards the train body; a bearing assembly, located below the buffer assembly and providing support for the buffer assembly; the bearing assembly is in mutual contact with the buffer assembly, the bearing assembly is mutually and horizontally rotatably connected with the connection assembly, the bearing assembly and the connection assembly have a second rotation center, the second rotation center is located at a second side of the connection surface towards the buffer assembly; and a self-adaption assembly, the bearing assembly is connected with the buffer assembly by the self-adaption assembly. a first connection part, the first connection part is mutually and horizontally rotatably connected with the buffer assembly, and the first connection part and the buffer assembly have a first rotation center; a second connection part, the second connection part has a connection surface, the second connection part is connected with a train body through the connection surface, and the first rotation center is located at a first side of the connection surface towards the train body; a bearing assembly, located below the buffer assembly and providing support for the buffer assembly; the bearing assembly is in mutual contact with the buffer assembly, the bearing assembly is mutually and horizontally rotatably connected with the connection assembly, the bearing assembly and the connection assembly have a second rotation center, the second rotation center is located at a second side of the connection surface towards the buffer assembly; and a self-adaption assembly, the bearing assembly is connected with the buffer assembly by the self-adaption assembly.