The invention discloses a method for promoting sunflower cesium or/and strontium enrichment by use of a plant growth regulator. The method is characterized by comprising the following steps: planting sunflowers in soil containing pollutants-cesium and or/strontium, and spraying the plant growth regulator; when the plant-sunflowers grow to the maturation stage, removing the whole or overground parts of the plants-sunflowers from the polluted soil; furthermore, planting the next batch of sunflowers, and spraying the plant growth regulator; when the new planted plants-sunflowers grow to the maturation stage, removing the whole of the plants-sunflowers from the polluted soil; and repeating the process until the content/contents of the cesium and/or the strontium in the soil reaches the standard for environmental safety. In the method disclosed by the invention, the cesium/strontium absorption ability of the sunflowers is obviously enhanced under the effect of the plant growth regulator so as to permanently solve the problem of cesium/strontium pollution of the soil; the method has the characteristics of low treatment cost, no damage to environmental soil structure, no secondary pollution and the like, and brings good environmental benefits, social benefits and economic benefits.