A jig device for a trunk lid includes a jig part capable of assembling a trunk lid to a trunk body of a vehicle in the state in which the trunk lid is closed, wherein the jig part is configured to include a jig body mounted on the trunk body, first and second jigs mounted on the jig body to determine a position of the trunk lid in a Y direction, a third jig mounted on the jig body to determine a position of the trunk lid in a Z direction, a fourth jig mounted on the jig body to guide the trunk lid in the Y direction, and a fifth jig mounted on the jig body to determine a position of the trunk lid in an X direction.