The invention discloses a high-efficiency photovoltaic grid connected inverter, and belongs to the technical field of power electronic converters. The high-efficiency photovoltaic grid connected inverter comprises a DSP controller, a first MOS pipe, a second MOS pipe, a transformer, a driving circuit, sampling circuits, an inductor, capacitors and a load, wherein the transformer comprises a primary winding and two secondary windings. In the field of photovoltaic power generation, a DC-DC conversion part is a key part of the inverter; at present, a DC-DC conversion part adopts a hard switching technology generally, so that the electric energy conversion efficiency is too low, and meanwhile, since voltage stress and current stress in a circuit are too high, relatively strong electromagnetic interference is caused. Therefore, an LLC resonant conversion technology is adopted, self parasitic parameters of components are fully used, the voltage stress and the current stress are reduced, a switching frequency can be equal to a resonant frequency, and the conversion efficiency is improved. The high-efficiency photovoltaic grid connected inverter is especially suitable for being used on occasions where requirements on the efficiency of the inverter are relatively high.