The invention discloses a noose transmission mechanical arm which comprises a drive module, an operating rod and an end mechanical arm, wherein, the end mechanical arm is arranged at the end of the operating rod, a noose transmission module is arranged between the drive module and the end mechanical arm, one end of the noose transmission module is connected with the drive module and the other end thereof is connected with the end mechanical arm, the noose transmission module contains eight nooses, the nooses consist of sleeves and ropes, and the ropes can be slidably arranged in the sleeves. The mechanical arm adopts the noose transmission mechanism which can realize remote transmission and has simple mechanical structure and flexible transmission route; the mechanical arm has the advantages of simple and reasonable structure, flexible action and being capable of operating in narrow space; when in operation, only a part of the noose transmission mechanical arm goes into the narrow space, therefore, the situation that the mechanical arm is incapable of being taken back in the event of failure does not occur; the mechanical arm is applicable to the relief work in the debris after a disaster, and can be also used for inspecting and maintaining a large transformer, clearing a pipe, and the like, which need to be operated in narrow space.