The invention discloses a flight system for removing a hanging object on a transmission line and a working method of the flight system. The flight system comprises a control device, a flight platform and an ignition system, wherein the flight platform and the ignition system are both connected with the control device, the ignition system is arranged on the flight platform and comprises a fuel injection device and an ignition device, the fuel injection device comprises an injection part used for injecting fuel to the hanging object, the ignition device comprises an igniter, the injection part can be opposite to the hanging object, and the igniter can be opposite to the hanging object. In the process of removing the hanging object on the high-altitude transmission line, the flight platform flies to a high position and gets close to the hanging object, then the fuel is injected to the hanging object, then laser rays are burst to the hanging object through the igniter, and the hanging object is subjected to spontaneous combustion at a high temperature to be removed. Thus, the removal efficiency of the hanging object can be greatly improved, and meanwhile work of the flight system is safer, higher in reliability and convenient to control.