For a photovoltaic inverter, the invention provides a new leakage current detection scheme including a leakage current detection circuit and a leakage current detection method with the adoption of the circuit. According to the scheme provided by the invention, a cobalt-based amorphous magnetic bead is replaced by a ferrite bead. Since the ferrite has rich sizes and is convenient to cut, the requirement of bandwidth detection can be satisfied in the condition of increasing the aperture. At the same time, an MCU is used as measurement and control units, the post-processing of data is convenient, such as the calculation of an effective value and a moving average value, and the operation of an inverter can be cut directly through the MCU when necessary.