LIFTING ARM AND LIFTING DEVICE

A lifting arm comprises: a straight arm (0100); a moving mechanism (0120), disposed on the straight arm (0100) and capable of linear movement, wherein an angle formed by the direction of linear movement and a vertical direction is not zero; a transmission pulley set (0130), comprising a first fixed pulley (0131) and a second fixed pulley (0132) and a moving pulley (0133), wherein the pulleys are parallel to each other in an axial direction, the first fixed pulley (0131) and the second fixed pulley (0132) are distributed, in a linear movement direction, on the moving mechanism (0120), and the moving pulley (0133) is configured to be connected to a load and to receive horizontal traction as input by a user; and a flexible member (0140), sequentially tensioned to the first fixed pulley (0131), the moving pulley (0133), and the second fixed pulley (0132), wherein one end of the flexible member (0140) is fixed to the straight arm (0100), and the other end is configured to receive a driving force to extend or retra