Automatic working system

The invention relates to an automatic working system. The automatic working system includes a boundary module and an automatic walking device; the boundary module includes a signal generating device which generates boundary signals with predetermined frequencies which comprise at least two characteristic frequencies appearing in succession, and a boundary line which plans a working area of the automatic walking device and is electrically connected with the signal generating device, and transmits the boundary signals and generates electromagnetic fields; the automatic walking device works in the working area according to preset programs and includes a detection unit which detects electromagnetic fields existing in an environment and converts the electromagnetic fields into corresponding detection signals, and a processing unit which is provided with a band-pass filtering function which adopts the preset frequencies as center frequencies, and receives the detection signals of the detection unit and filters signals outside the preset frequencies, and generates processing signals with the preset frequencies. The automatic working system has a strong anti-environmental disturbance ability.