The invention discloses a pure sine wave inverter having a pulse width modulation voltage sampling isolation function. The pure sine wave inverter comprises a power supply input module, an input isolation module, a pulse width modulation (PWM) module, a variable voltage rectification filtering module, a sinusoidal pulse width modulation (SPWM) driving module, an LC filtering module, a sine wave generator, an MCU and a voltage sampling module, the PWM module comprises a time-base circuit chip, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirty resistor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor, a twenty-sixth capacitor, a twenty-seventh capacitor, a twenty-eighth capacitor, an eleventh diode, a twelfth diode, a thirteenth diode, an eleventh triode and a twelfth metal oxide semiconductor (MOS) transistor, the voltage sampling module comprises a voltage comparison circuit, and the voltage comparison circuit comprises a voltage comparator, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor. By the pure sine wave inverter, the power supply input can be effectively isolated, a circuit is simple in structure design, the pure sine wave inverter has powerful functions, is flexible to use and is relatively wide in application range, signal interference can be avoided, accurate data acquired by an instrument is ensured, a control signal and a voltage sampling signal can be effectively isolated, and the sampling accuracy is improved.