Pressure control method and system introduced into beauty instrument

The pressure control method comprises the following steps that the pressure P of a gas tank of the beauty instrument is detected, and whether the pressure meets a threshold value P1 and a first derivative of the pressure value P or not is judged; judging whether the first-order derivative reaches a threshold value A or not and whether the first-order derivative is in a normal operation state or not, maintaining the current situation of the air compressor, starting the stepping motor to operate for N steps, and entering a nursing state; in the nursing process, the actual pressure P is further detected, the relation between the actual pressure P and the threshold value P1 is judged, the first-order derivative threshold value of the detected pressure P is further judged, and the rotating speed of the air compressor is increased or decreased according to the judgment result. According to the method, the threshold range P1 of the operating pressure P is set, first-order derivative judgment is conducted on the oper