The invention relates to a damp adjustable plunger latch which comprises a plunger latch body mounted on a door plate and a handle for opening and closing the plunger latch. The damp adjustable plunger latch also comprises a damp adjusting ring for adjusting the rotating damp of the handle. The handle comprises a rotary shaft and a handle body; the damp adjusting ring which is annular is arrangedon the rotary shaft in a sleeving mode and is located between the plunger latch body and the handle body; the damp adjusting ring comprises a sliding round groove, a limiting round groove, a sliding block, a second limiting bolt, a torsion spring, a limiting screw and a suction disc. According to the damp adjustable plunger latch provided by the invention, the rotating damp of the handle is increased properly by means of the damp adjusting ring. The torsion of the plunger latch is adjusted by replacing different torsion springs or the total torsion of the plunger latch is adjusted by increasing or decreasing the torsion springs in different quantity, so that the damp of the rotary handle is adjusted. Moreover, the damp adjustable plunger latch has the characteristic being convenient to mount.