The DHT11 temperature and humidity sensor includes a temperature and humidity composite sensor with calibrated digital signal output. It has the advantages of excellent quality, ultra-fast response, strong anti-interference ability and high cost. The DHT11 temperature and humidity sensor needs to be called these calibration coefficients when processing the detection signal. The single-serial serial interface makes system integration simple and fast. And it has a very small size, low power consumption, and signal transmission distance up to 20 meters or more.