The invention relates to a multi-degree-of-freedom mechanical arm. The multi-degree-of-freedom mechanical arm comprises a supporting base, a rotary mechanism, a telescopic mechanism, a pitching drive part, a folding mechanism, a rotary mechanism, an opening-closing mechanism and a mechanical claw, wherein the rotary mechanism is arranged on the bottom of the supporting base; one end of the telescopic mechanism is hinged with the supporting base; one end of the pitching drive part is hinged to the top of the supporting base, and the other end of the pitching drive part is hinged with the telescopic mechanism; the folding mechanism is arranged at the other end of the telescopic mechanism; the telescopic mechanism drives the folding mechanism to linearly move; the rotary mechanism is connected with the folding mechanism; the opening-closing mechanism is arranged at the output end of the rotary mechanism; the mechanical claw is connected with the opening-closing mechanism; and the opening-closing mechanism drives the mechanical claw to open or close. The multi-degree-of-freedom mechanical arm can perform six-degree-of-freedom compound motion, and can be suitable for construction operation of a complex environment.