Concealed vertical up and down mechanism

The utility model belongs to the riser field and specifically relates to a concealed vertical up and down mechanism of a riser. The concealed vertical up and down mechanism comprises guide frames, a landing gear, an elevating mechanism and a locking mechanism. The guide frames are vertically equipped inside a ground pit. The landing gear is slidingly equipped inside the guide frames. The elevating mechanism comprises an upright screw rod, a gearbox connected with the screw rod and a motor, wherein, the screw rod is connected with a base plate. The gearbox and the motor are equipped on the landing gear. The motor controls the screw rod to drive the landing gear to elevate through the gearbox. The locking mechanism comprises a lock pin and a locking cylinder. A groove which is equipped on the side surface of the landing gear and the guide frames cooperates with the lock pin for locking. The concealed riser vertical up and down mechanism in the utility model can make a hydraulic cylinder vertically lifted out of