Hoisting arm and hoisting device

The invention discloses a hoisting arm. The hoisting arm comprises a straight arm, a moving mechanism, a transmission wheel set and a flexible component. The moving mechanism maintains on the straightarm in a manner that the moving mechanism can linearly move, and a nonzero included angle is formed between the linear movement direction and the vertical direction. The transmission wheel set comprises a first fixed wheel, a second fixed wheel and a movable wheel, wherein every two of the first fixed wheel, the second fixed wheel and the movable wheel are parallel with each other in the axial direction; the first fixed wheel and the second fixed wheel are distributed on the moving mechanism in the linear movement direction; and the movable wheel is used for being connected with a weight andreceiving the horizontal traction force input by a user; The flexible component is sequentially tensioned by the first fixed wheel, the movable wheel and the second fixed wheel. One end of the flexible component is fixed to th