The invention discloses a current forecasting hysteresis control method of an active power filter, belonging to the field of electric energy quality control of a power grid. In the method, the generation reason of errors in the traditional hysteresis control is analyzed, an output current forecasting model is built on the basis of the kinetic equation of the active power filter, an instruction current is forecast by linear interpolation, and the working properties of the current forecasting hysteresis control are analyzed. The invention designs an active power filter (APF) controller based on a Compact RIO platform of NI Company and therefore ameliorates the control errors of the hysteresis control, which has a very high engineering practice value for improving the control accuracy of the active power filter.