The invention relates to a brushless direct current pure signal switch. The brushless direct current pure signal switch comprises a base, a cover plate, a button, a main spring, a connector, a push rod, sliding elastic sheets and a reversing mechanism; the reversing mechanism comprises a shifting handle and a small switch; when the shifting handle is shifted to one side, the small switch is not incontact with the shifting handle, and the small switch is in a disconnected state; when the shifting handle is shifted to the other side, the small switch is in contact with the shifting handle, andthe button of the small switch is pressed down to enable the small switch to be switched on, and a signal conversion function is realized after the small switch is switched on; the brushless direct current pure signal switch also comprises a PCB; the PCB is provided with a copper plate and a carbon film strip; the push rod is driven through the button; the push rod drives the two groups of slidingelastic sheets; and one group of the sliding elastic sheets is in contact with the copper plate on the PCB to realize switch-on of an electric signal while the other group of the sliding elastic sheets is in contact with the carbon film strip on the PCB to realize a resistance adjustment function. The brushless direct current pure signal switch is directly welded on the external PCB through a positioning column, so that automation can be realized more easily when the board is welded by a consumer; and in addition, the reversing operation is realized by adopting the small signal switch, so that the reversing function can be realized in a narrow space, and safety and reliability are achieved.