A multipath differential pressure gauge comprises a housing. An inner side of the housing is sleeved by a glass tube. An inner cavity is disposed in the glass tube. An outer side wall of the glass tube is fixedly connected with scales via fasteners. Two ends of the housing are fixedly connected with flanges via fasteners. The center of each flange is rotatably connected with a vertically arranged valve core. A side wall of each valve core is provided with a connecting hole. A side wall of each flange is provided with a first interface, a second interface, a third interface and a fourth interface. The first interface and the second interface are both connected with the inner cavity via the connecting hole. The third interface and the fourth interface are both connected with the inner cavity. The third interface is fixedly connected with a screwed plug. The fourth interface is fixedly connected with a cone valve. A piston is disposed in the glass tube. A large spring is disposed between the piston and the flange. Two ends of the differential pressure gauge are respectively provided with three-phase two-way valves. Through switching of the two reversing valves, detection of different differential pressure values in three paths of pipelines can be achieved without detaching the differential pressure gauge, so that one differential pressure gauge can detect pollution degree of filter cores in multiple pipelines.