The invention relates to a method for utilizing a buffer strip to control agricultural non-point source pollution of a tidal river network area of a plain, belonging to the technical field of environmental protection. The method comprises the following steps of: selecting buffer strip areas, carrying out primary treatment to the buffer strip, setting a water distribution system of the buffer strip, selecting and planting plants in the buffer strip and introducing water source into the buffer strip. The method has the characteristics of simpleness, convenience, practicability, good purifying effect and free maintenance management.