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 . <EOS>