An electromagnetic pump has a frequency converter circuit for driving the electromagnetic pump, wherein the frequency converter circuit comprises an oscillator circuit, a bistable circuit and a push-pull circuit. The oscillator circuit oscillates to transform DC into a single-phase oscillating signal. The bistable circuit splits the single-phase oscillating signal into a N-phase stimulus signal and a S-phase stimulus signal. The push-pull circuit amplifies and transports the N-phase stimulus signal and the S-phase stimulus signal to the electromagnetic pump to make the swing arms of the electromagnetic pump swinging effectively, wherein the swing speed, the swing frequency and the swing amplitude of the swing arms vary with the change of the oscillation frequency of the oscillator circuit. Thereby, the suction pressure and the discharge pressure of the electromagnetic pump could further be adjusted higher or lower, wherein said frequency converter circuit comprises a modulation circuit, which could change the swing speed of the swing arms swinging outwardly or inwardly to further increase or decrease the suction pressure or the discharge pressure.