The touch button is realized by the touch chip. The principle of the touch chip is to change the input capacitance through the touch of the human finger. The input capacitance is compared with the built-in reference capacitance of the touch chip to output a differential signal, and then amplified by the amplifier circuit to obtain the high and low level at the output end, thus realizing the simulation Signal control. The main MCU detects the level signal of the output port of the touch chip to determine whether there is a finger touched the button and realize the touch button function.