To improve the efficiency of island detection and the quality of current waveform, a new current disturbance strategy is proposed based on the traditional AFD. As to the traditional AFD, the rising of chopping fraction (cf) leads to more current distortion and the smaller cf resulted in low efficiency of island detection. Therefore, it’s difficult to achieve good balance between the efficiency of island detection and current distortion in anti-islanding detection. Now the proposed current perturbation method can effectively improve the THD of stable current by applying variable step disturbance on grid current. And the new method also improves the rate of detection by strengthening disturbance in negative half wave. Theoretical analysis and simulation experiment prove the validity and reliability of the strategy.