The invention discloses a beat generator which comprises two waveform generators, wherein the structure of each waveform generator is characterized in that: a resistor R1 and a capacitor C1 are connected in parallel; one end of the resistor R1 is grounded, and the other end of the resistor R1 is connected with a capacitor C2 in series, and is connected with an operational amplifier; the capacitor C2 is connected with an adjustable resistor RP1 in series; the adjustable resistor RP1 is connected with an adjustable resistor RP2 in series, and is connected with the operational amplifier A; the adjustable resistor RP2 is connected with a resistance R2 in series; the resistor R2 is grounded; the operational amplifier is connected with a loudspeaker; a frequency meter is connected between the operational amplifier and the loudspeaker; a power source provides power for the operational amplifier and the loudspeaker. The beat generator is reasonable in structure and good in use effect.