An assembly jig for pins includes a jig body in which pin insertion recesses, into which respective pairs of pins and interpieces are inserted, are aligned at predetermined intervals, and urging devices that urge lower end portions of both the pins and the interpieces, which are fitted in the pin insertion recesses, in the direction perpendicular to the axial direction of the pins and the interpieces. In the jig body, urging device installation recesses are formed so as to be contiguous with the consecutive pin insertion recesses. Each urging device is arranged in the corresponding urging device installation recess, and includes a helical compression spring of which the urging direction is the radially outward direction, and a pressing member urged by the helical compression spring. The pressing member has a first pressing face that contacts the pin, and a second pressing face that contacts the interpiece.