Drainage gas production plunger in gas well

The invention discloses a drainage gas production plunger in a gas well, which is applied to continuous efficient plunger drainage gas production of drainage gas production in a gasser. At least one sealing ring is sleeved on the outer wall of a main drum; the lower end of the main drum is in external threaded connection with a lower base, and the wall of the lower base is provided with a communication pore; a switch valve rod is arranged on an annular step at the lower end of the lower base, a cylindrical rod at the lower end of the switch valve rod passes through a centre hole at the annular step at the lower end of the lower base, and the upper end face of the switch valve rod is embedded with a sealing ring; the lower end face of an annular step at the lower end of the main drum is provided with a downward annular bulge; and the annular bulge at the lower end of the main drum is opposite to the sealing ring at the upper end of the switch valve rod. The invention has the following effects ...