System and method for displaying air quality

The invention discloses a system for displaying the air quality, which comprises a power supply module, a sensor module, a microcontroller, a display module, an audible alarm circuit and an alarm, wherein the power supply module receives the externally-input power supply voltage and respectively outputs the working voltage to the microcontroller and the sensor module; the sensor is connected with the microcontroller; the display module and the audible alarm circuit are respectively connected with the microcontroller; the alarm is connected with the audible alarm circuit; the sensor module is used for detecting the environmental air quality and outputting the corresponding detection signals to the microcontroller according to the detected air quality result; and the microcontroller controls the display module according to the detection signals of the sensor module, displays the detected air quality and can control the audible alarm circuit and the alarm to sound an alarm when the detected air quality is poorer. The invention also discloses a method for displaying the air quality.