Coupler assembling method of built-in axle box bogie driving device

The invention provides a coupler assembling method of a built-in axle box bogie driving device. The coupler assembling method comprises the steps that a gearbox is adjusted to be in a horizontal state, and the first height from the gearbox to a rail surface is obtained through measurement; the traction motor is horizontally placed on the lifting supporting vehicle, the second height from the traction motor to the rail surface is measured, and the output shaft of the traction motor and the input shaft of the gearbox are adjusted to be consistent in height according to the difference value between the second height and the first height; measuring the axial distance between the traction motor and the gear box, and determining the thickness of the gasket according to the axial distance; the traction motor and the gear box are fixedly connected through the elastic rubber nodes, the whole bogie is hoisted to the rotating wheel tool, and the flange connecting holes of the coupler are sequentially rotated to the posi