Double-frequency excited soil moisture detector

The double-frequency excited soil moisture detector comprises a shell, a touch screen, a battery, a power switch, a probe and a circuit board unit, the touch screen and the power switch are mounted atthe top of the shell, the circuit board unit and the battery are mounted in the shell, the probe is mounted at the lower part of the shell, and the circuit board unit is mounted in the shell. A positive plate and a negative plate are arranged in the probe and electrically connected with the circuit board unit, and the touch screen, the battery and the power switch are also electrically connectedwith the circuit board unit. The circuit board unit comprises a voltage stabilizing source unit, a single-chip microcomputer, a square wave signal source unit, a frequency selection analog switch, a precision resistor R, a wave crest detection unit and a temperature sensor. The capacitive probe is not easy to wear, the circuit is simple, the capacitance value of the probe can be effectively measured, the conductivity resis