Coal-bed gas well under-pressure operation device

The utility model discloses a coal-bed gas well under-pressure operation device, which is characterized in that a three-ram blowout preventer and an energy accumulator are connected below a lower cross beam, the lower cross beam is fixedly connected with a cylinder body of a lifting oil cylinder, a piston rod of the lifting oil cylinder is connected with a traveling cross beam, and the traveling cross beam is fixedly connected with the energy accumulator. The lifting oil cylinder provides acting force needed by downward pressing and upward lifting of a tubular column, a traveling universal slip is installed on the traveling cross beam, the double-ram blowout preventer is connected to the upper portion of the traveling universal slip, the top end of the telescopic joint assembly is connected with the traveling cross beam, the bottom end of the telescopic joint assembly is connected with the annular blowout preventer, and the annular blowout preventer is connected with the telescopic joint assembly. The annular