A device for operating under pressure for oil production and gas wells, comprising a lifting rod for taking and releasing a back pressure valve, a cylinder for installing the lifting rod, and a tool joint arranged at the lower end of the lifting rod. The cylinder includes an upper cylinder and a lower cylinder, and is characterized by , The upper cylinder is provided with an upper flange, and the lower cylinder is provided with a lower flange. The upper flange and the lower flange are connected and supported by a pair of double-headed screws. The lifting rod is provided with clamps and rubber sleeves; the upper cylinder body and the lower cylinder body are connected through a pipeline, and the pipeline is connected by six connecting pipes in sequence; the lifting rod slides freely in the upper cylinder body and the lower cylinder body. Advantages: The split design is adopted, the support between the upper cylinder and the lower cylinder is fixed by a double-head screw, and the pipeline is connected by several connecting pipes in sequence. The connecting pipe is directly detachable, which saves material during production. It is also convenient for processing and disassembly, which reduces costs.

Sovereignty items: 1. An oil and gas wellhead operating device under pressure, including a lifting rod for taking and releasing a back pressure valve, a cylinder for installing the lifting rod, and a tool joint set at the lower end of the lifting rod. The cylinder includes an upper cylinder and a lower The cylinder body is characterized in that the upper cylinder body is provided with an upper flange, and the lower cylinder body is provided with a lower flange. The upper flange and the lower flange are connected and supported by a pair of double-headed screws. There are clamps and rubber sleeves on the lifting rods between the lower cylinders; the upper cylinder and the lower cylinders are connected by a pipe, and the pipes are connected by six connecting pipes; the lifting rods are connected to the upper cylinder and The lower cylinder slides freely.