The present invention provides a device and method of vehicle autonomous wire assembling and disassembling of an unmanned aerial vehicle with a hanging wire. The device comprises a robot transport platform, and the robot transport platform comprises a carrying platform main body, a rotor fixture platform, a telescopic equipotential handgrip, a tumble pulley suspension device, an insulation rope push device, a balance control device and a robot locking device. The method comprises: a, the middle portion of an insulation pulling rope 603 is hanged on a high-voltage transmission line 602 through an unmanned aerial vehicle, and two ends of the insulation pulling rope 603 are arranged on the ground; b, a tumble pulley is employed to perform wire hanging; c, the robot transport platform performs wire assembling, d, a hot-line work robot performs wire assembling, e, the hot-line work robot is prepared to separate from the rotor transport platform, and f, the hot-line work robot performs wire disassembling which is opposite to the flow mentioned above. The device and method of vehicle autonomous wire assembling and disassembling of the unmanned aerial vehicle with the hanging wire realize the whole process of the wire assembling and disassembling of the hot-line work robot to realize wire assembling maintenance efficiency and practical level of the hot-line work robot.