Folding arm crane

A folding arm crane comprisies a swivel joint comprising a first horizontal arm, a second horizontal arm and an articulated shaft for articulating the two horizontal arms; a flexible transmission mechanism comprising a fixed wheel set, a horizontal moving wheel and a flexible component, wherein the fixed wheel set is arranged on the articulated shaft and comprises axial vertical fixed wheels arranged in a pair, the horizontal moving wheel is axially disposed horizontally on the second horizontal arm, the flexible component is sequentially connected with the first horizontal arm, any one of thepaired vertical fixed wheels and the horizontal moving wheel in the tension mode, and the flexible component can be linearly and reciprocally held between the pair of vertical fixed wheels; a position compensating mechanism comprising a cam and a follower set, wherein the cam is disposed on the articulated shaft, and the follower set is driven by the cam to drive the horizontal moving wheel to move up and down relative t