The invention belongs to the technical field of underground coal gasification, and discloses a movable ignition system, device and method for underground coal gasification. The movable ignition system comprises a movable ignition device control module, a high-pressure combustible agent pipeline module, a temperature sensor module, a ventilation module, a power supply module, an electromagnetic heating igniter and a crawler belt moving module. According to the movable ignition system, device and method for underground coal gasification, ignition can be carried out in a movable mode as required under the condition that a large amount of underground water exists at the designed ignition position, and the problem that secondary ignition cannot be rapidly conducted after primary ignition fails in the traditional ignition technology is solved; an electromagnetic induction heating system can well protect an igniter structure and is stable in ignition, the ignition defect existing in electric ignition and other methods is effectively avoided, and the movable ignition device can be used repeatedly; under the dual action of a temperature control switch and a temperature sensor, fuel gas conveying is controlled, stable flames are formed, and the burning explosion phenomenon is eradicated; and a crawler-type moving system can pass through a complex structure in a drill hole or a sleeve, so that the operation is convenient.