The invention discloses a method for guiding plugging agents into an oil well for water plugging by radial wells, and belongs to the field of oil production engineering in oil development. The methodcomprises the following step that the orientation of the radial wells, the length of the radial wells, numbers of the radial wells, dosage of the plugging agents and injection displacement are determined. The method for guiding the plugging agents into the oil well for water plugging by the radial wells changes the flow line of the plugging agents along a producing well as radial flow in a traditional general injection method to the radial flow along the radial wells in a flow advantage band, the precise delivery of the plugging agents is realized, and the damage to an oil reservoir is reduced. The radial wells have high flow conductivity and can be regarded as pipe flow, compared with the formation seepage flow, the injection pressure to the depth of the formation is greatly reduced, andthe effects of decompression and increasing injection are achieved. The method for guiding the plugging agents into the oil well for water plugging by the radial wells can realize the precise deliveryof the plugging agents in the flow advantage band and the decompression and increasing injection, and is of great significance for improving the water plugging effect of the oil well.