Abstract: In order to help students better understand the knowledge of frequency demodulation and master different frequency demodulation schemes, a set of phase/proportional frequency discrimination comprehensive experimental circuit is designed. The frequency modulation wave generated by the signal source is used as the circuit input, and the flexible switching between the proportional frequency discriminator and the superimposed phase frequency discriminator is realized through the selection switch, so as to achieve the organic combination of the two circuit forms. Through the test and analysis of the frequency discrimination function, frequency discrimination sensitivity and amplitude limiting function, this paper deeply discusses the similarities and differences between the two frequency discriminators, so as to realize the integration of theory and practice. The teaching practice shows that the experiment has good effect and is suitable for many occasions, such as undergraduate experimental teaching, college students’ scientific research and electronic design competition.