Disclosed is a hydrate kinetic inhibitor of a structural formula as represented by formula I. The inhibitor has a good water solubility, a high inhibitory activity, a capability of achieving a good inhibitory effect, a small usage amount and a reduced cost; has the advantages of a low dosage, a high efficiency, an extensive applicability, etc.; can effectively delay the hydrate nucleation time and reduce the hydrate generation rate in an environment of a high degree of undercooling at a low dosage concentration (0.1-10 wt%); is suitable for an oil-gas-water three-phase or oil-water or gas-water two-phase coexistence system; is applied to the inhibition of the generation of hydrates during the exploration, processing and transportation of oil and gas, without subjecting to undercooling and application constraints; and has a broad prospect of application. In formula I, R is *(CH2)m*, m = 1-5, and n = 10-10000.