The utility model relates to a simple and easy dismounting device of large -scale shaft coupling belongs to coupling dismantling device technical field, the technical problem that will solve does: theutility model provides a simple structure dismantles labour saving and time saving's simple and easy dismounting device of large -scale shaft coupling, the problem of this technique is solved the technical scheme who adopts does: the relative parallel arrangement of face of two connecting plates, the one end of connecting plate is provided with first through -hole, and the other end is provided with the second through -hole, first U -shaped board sets up with the opening part of second U -shaped board relatively, and the outside extension end of first U -shaped board is provided with first engaging lug, and the outside extension end of second U -shaped board is provided with the second engaging lug, and first engaging lug together inserts first through -hole with the second engaging lug,the crossbeam passes the second through -hole, connects two connecting plates as an organic whole, central beam is fixed to be provided with hydraulic jack, the last ejector pin that is provided withof hydraulic jack, and the ejector pin is to direction along the axis direction level motion of first U -shaped board with second U -shaped board, the utility model discloses be applied to the dismantlement shaft coupling.