An electrodeless lighting system and its control method are disclosed. When the electrodeless lighting system starts, a larger amount of filament current of a magnetron is applied to stably drive the magnetron, and when the electrodeless lighting system operates normally, a smaller amount of filament current is applied, thus avoiding interference with a wireless LAN, lengthening a life span of the magnetron, reducing noise, and improving an operational efficiency of the electrodeless lighting system.