The invention discloses a grid-connected operation method of a grid-connected type photovoltaic inverter, comprising the following steps: AD sampling is carried out on a DC voltage signal obtained by the detection of a DC voltage signal detection unit and an AC voltage signal obtained by the detection of an AC voltage signal detection unit, and the voltage signals are sent to an inverter control circuit for processing, and the inverter control circuit is also used for controlling the operation of the converter; when the inverter waits for a starting command, an AC contactor is kept in an off state; after the inverter responses the command to start, the DC bus voltage Udc obtained by carrying out AD sampling on the DC input side of the inverter is higher than the starting voltage Ua of theinverter, then the inverter performs off-grid independent operation and controls the AD output voltage Uout of the inverter to be close to the grid voltage Unet until the DC bus voltage Udc is maintained to be higher than the minimum operating voltage Ub for a time of t, the inverter control circuit controls the suction of the AC contactor to perform grid-connected power generation; and if the DCbus voltage Udc is lower than the minimum operating voltage point Ub, the inverter stops independent operation.