Universal manipulator

The utility model discloses a universal mechanical arm which comprises a rotating support, a main connecting plate, a balance air cylinder, an upper balance arm, a lower balance arm, a balance arm connecting piece, a terminal arm and a lower rotating driving device. The upper portion of the rotating support is connected with a stand column of a track system arranged above the mechanical arm, the lower portion of the rotating support is fixedly connected with the two main connecting plates, the two main connecting plates are arranged in parallel in a spaced mode, and the upper balance arm, the lower balance arm and the balance air cylinder are all arranged between the two main connecting plates. The upper balance arm and the lower balance arm are parallel to each other, one end of the upper balance arm and one end of the lower balance arm are connected with the two main connecting plates through a connecting pair, the other end of the upper balance arm and the other end of the lower balance arm are fixed throu