Disclosed is a hydrate kinetic inhibitor of a structural formula as represented by formula I. The inhibitor of the present invention 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 be used in an environment of a high degree of undercooling at a low dosage concentration (0.1-10 wt%); can effectively delay the hydrate nucleation time and reduce the hydrate generation rate; 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. wherein n = 100-40000, R is *(CH2)m*, and m = 1-5.