The invention discloses a novel scale inhibitor and application thereof, belongs to the field of water treatment, and aims to solve the problem that the existing scale inhibitor for industrial circulating water is generally a compound scale inhibitor formed by mixing a plurality of substances and is large in use amount. The novel scale inhibitor is a single-component scale inhibitor, and the molecular formula of the scale inhibitor is O,O'-diisopropyldithiophosphate triethylamine. The scale inhibitor has the advantages of being single in component, small in dosage, high in scale inhibition efficiency, stable in performance, good in water solubility and easy to use. The scale inhibitor can improve the recycling rate of circulating water and reduce the consumption of water resources. The novel scale inhibitor is suitable for scale inhibition of circulating water, is especially suitable for scale inhibition of circulating water in the fields of oil field sewage systems, small boilers, heating networks and the like, has wide application values and good application prospects, can bring remarkable economic benefits and social benefits, and is worthy of large-scale popularization and application.