Mechanical arm and robot

The invention discloses a mechanical arm. The mechanical arm comprises a first arm component, a second arm component, a pivot base, a third arm component and a drawn wire, wherein the second arm component is rotationally connected with the first arm component through a first rotating shaft; the first rotating shaft is substantially perpendicular to the length directions of the first arm component and the second arm component; the pivot base is rotationally connected with the second arm component and the third arm component; and the drawn wire is fixedly connected with at least one of the first arm component, the second arm component and the third arm component. The mechanical arm can enable the arm component connected with the drawn wire to rotate corresponding to the other arm component through pulling the drawn wire; and under the condition, a driving device for pulling the drawn wire can be not limited to arrange in the rotary connecting place of the two arm components, but is arranged out of the mechanica