The present invention relates to a power fetching system for a no neutral switch and a control method thereof, and a no neutral switch, wherein the power fetching system is connected to an electrical device and a wireless controller, and the wireless controller controls a switch module for changing an operating state of the electrical device. The power fetching system includes: a power fetching module, connected between a power source and the wireless controller, the power source supplying power to the wireless controller and the electrical device, where the power fetching module is configured to obtain power from the power source and supply the obtained power to the wireless controller during energization of the electrical device; and a control module, connected to the power fetching module, and configured to detect power consumption of the wireless controller and provide a control signal to the power fetching module according to a change in power consumption of the wireless controller to adjust the power obtained by the power fetching module from the power source.