Abstract: The control strategy for the photovoltaic inverter under unsymmetrical fault in power grid is focused on.A mathematical model of the grid-connection inverter when unsymmetrical fault occurs in the grid is built and an analysis of power characteristic is made.Then the photovoltaic inverter control strategy based on model prediction current is put forward.Simulation verifications and analysis of damping active power fluctuation and negative sequence component current are made on a PSCAD/EMTDC platform.The results show that the model prediction current control method is able to make the output current of the inverter quickly follow the reference current with good dynamic and static characteristics. Under the unsymmetrical fault in the grid,it effectively realizes the control of each sequence current without decomposing the grid current phase sequence,thus restraining active power fluctuation and negative sequence current caused by the unsymmetrical fault.Simple and easily processed digitally,this method is of great engineering value in photovoltaic inverter control.