The interleaved parallel flyback grid-connected micro inverter is focused on, and then the power loss calculation and the analysis of the efficiency are discussed in detail. First, the structure and principle of the single-phase grid-connected micro-inverter is described. And the operation principle of the active clamp circuits applying to flyback converter is presented, these active clamp circuits can recycle the leakage energy, and achieve the soft switching for the main switches in flyback-type micro inverter. Second, the power losses of main parameters including the high-frequency transformer, power devices, and ect. are analyzed and the detailed formulas given in the paper. Finally, the experimental results verify the feasibility of the efficiency analysis.