Height-adjustable mechanical arm

The utility model discloses a height-adjustable mechanical arm, which relates to the technical field of mechanical arms and comprises a mounting cylinder, the interior of the mounting cylinder is in a hollow state with an opening at the top, an axial partition plate is fixedly mounted in the mounting cylinder, and the inner space of the mounting cylinder is divided into a first mounting groove and a second mounting groove by the partition plate. An axial moving pipe is slidably connected into the first mounting groove, the top end of the moving pipe extends out of the mounting cylinder through the first mounting groove, a mechanical arm body is fixedly mounted at the end, extending out of the first mounting groove, of the moving pipe, and an axial supporting piece is arranged between the moving pipe and the first mounting groove; according to the height-adjustable mechanical arm, an operator can adjust the height of the mechanical arm body according to needs, driving of a motor, a hydraulic rod, an air cylind