Voltage tracking audio automatic amplitude limiting circuit

The invention discloses a voltage tracking audio automatic amplitude limiting circuit, which comprises a voltage comparison circuit module used for detecting the rising and falling change of an input voltage, comparing the input voltage with a reference voltage and outputting a voltage difference; the voltage tracking circuit module is used for tracking the voltage output by the voltage comparison circuit module and adjusting the conduction amount of an optocoupler; and the audio amplitude limiting circuit module is used for carrying out real-time amplitude limiting on the input audio signal according to the optocoupler conduction amount output by the voltage tracking circuit module. According to the invention, the gain of the circuit can change along with the intensity of an input signal; when a weak signal is input, the gain of the circuit is high; when a strong signal is input, the gain of the circuit is low, so that the influence of the intensity change of the input signal on an output signal is reduced,