This paper USES NE555N oscillator to convert the current signal collected by chr-01 humidity sensor into frequency signal. To collect the temperature and humidity signal. Because the resistance of many components to be used this time will change with the environmental humidity, the oscillation circuit designed by us will produce different oscillation frequencies. Then the signal through the photoelectric coupling and interface components transmitted to the SCM timer, we can complete the collection of temperature and humidity. The implementation circuit is shown in figure 4.2.