The invention provides an anti-countercurrent control method, device and system for a photovoltaic power generation system. Maximum output power Pn-max is taken as an output power command value of a full-power inverter and a limit power output value Pn is taken as an output power command value of a non-full-power inverter under the condition that the full-power inverter exists in the photovoltaicpower generation system; a superposition algorithm is adopted to update the limit power output value Pn for the non-full-power inverter, and a sum sigmadeltaPn of to-be-compensated power deltaPn of the full-power inverter is distributed to the non-full-power inverter; the distribution of active power of the inverter is carried out in a recursion mode until sigmadeltaPn is equal to 0, the output power command value is issued to the corresponding inverter, and finally, the under active power of each full-power inverter is distributed to each non-full-power inverter, so that the total power output value of the photovoltaic power generation system tends to be equal to the sum of the limit power output values Pn of all inverters which are originally determined, the active power P of a feeder network tends to be zero, and the possibility that electricity is taken out of a power grid for a long time is reduced.