The invention discloses an automatic feeding device for a pressure gauge assembler. The device comprises a first conveying belt, a fixed base, a pressure gauge and a rotating base; the pressure gaugeconsists of a bottom cover, an upper cover and a fixed outer edge; the fixed outer edge is arranged in the connecting place between the bottom cover and the upper cover; the rotating base is arrangedin the fixed base; a support ring is arranged at the upper end of the rotating base; a conveying table is arranged at the upper end of the support ring; the first conveying belt is arranged on one side of the conveying table; a second conveying belt is arranged at the upper end of the first conveying belt; the first conveying belt and the second conveying belt are connected through fixed rods; andthe fixed rod near one side of the conveying table is higher than the fixed rod on the other side of the first conveying belt. The device is simple in operation, high in comprehensive practicabilityand prone to popularization and application.