The invention provides a parameter extraction circuit for a broadcast supervision receiver and a parameter extraction method thereof, which belong to the field of communication and circuits. The parameter extraction circuit mainly comprises a power circuit, a detection circuit, a low-frequency amplifier circuit and a signal output circuit, wherein the power circuit provides power for the detection circuit, an operational amplifier circuit and the signal output circuit; the detection circuit receives target intermediate-frequency signals in need of parameter extraction and sequentially carries out rectification, signal amplification and filtering; signals after detection are inputted to the low-frequency amplifier circuit for low-frequency amplification; signals after low-frequency amplification are inputted to the signal output circuit; the signal output circuit processes the received signals and outputs audio signals, and the peak voltage, the valley voltage, and the mean voltage of detection signals after low-frequency amplification are outputted at the same time. The broadcast supervision receiver parameter extraction method comprises steps of signal input, rectification, signal amplification, filtering, low-frequency amplification, signal voltage extraction and audio output.