The invention belongs to the technical field of funnel assembly welding equipment for a stone ballast hopper car, particularly discloses a funnel assembly jig for a 1000mm-track-gauge stone ballast hopper car, and aims to solve the problem that the existing funnel assembly technique has great difficult and the existing assembly jig and method cannot satisfy positioning and assembly of the funnel of the type of car. The funnel assembly jig comprises a bottom frame, side upright posts, a median septum positioning plate, an end septum positioning plate, an integral bottom positioning plate, a horizontal positioning base, a horizontal positioning base, a jumble beam positioning device, a bidirectional air cylinder horizontal clamping device, a foldable pneumatic clamping device and a rotatable pneumatic clamping device. The funnel assembly jig disclosed by the invention is capable of improving the funnel assembly efficiency for at least three times.