The invention discloses a zero input ripple and polarity reversal output-type micro inverter, which comprises a DC power supply, an input capacitor, a cutoff diode, a primary-side switch transistor, adecoupling inductor, a decoupling diode, a decoupling capacitor, a decoupling switch transistor, an isolation transformer, a secondary-side diode, a filter capacitor, a power frequency polarity reversal inverter bridge, an output filter circuit and a power grid. A decoupling circuit formed by the decoupling inductor, the decoupling diode, the decoupling capacitor, the decoupling switch transistorand an isolation transformer auxiliary winding is added to the input side of the inverter, power ripples caused by AC output power at the input side of the DC power supply can be effectively decoupled, an electrolytic capacitor with a large volume and low reliability can be prevented from being adopted as a decoupling capacitor, and the purpose of prolonging the service life of the micro inverteris achieved.