The invention relates to a grid-connected converter with a VSG characteristic and an island identification method and device thereof. The grid-connected converter adopting a VSG technology is adopted,the small-amplitude forward voltage disturbance or negative voltage disturbance on the voltage of the power grid is performed through the voltage disturbance method on the power grid side, and the disturbed voltage is used as the output voltage given reference value of the grid-connected converter, and when the grid side voltage after the voltage continuous disturbance is larger than the first voltage threshold value or smaller than the second voltage threshold value, the island is determined. According to the method, the island phenomenon can be rapidly recognized, the disturbance voltage issmall every time, the stability and the reliability of a power grid system are not influenced.