To solve the problem of hydrate blockage in wellbore pipelines, a polymeric dynamic hydrate inhibitor, poly N-vinylpyrrolidone/N-vinylcaprolactam/dodecyl polyoxyethylene ether methacrylate (PNVP/NVCL/BEM), was studied through molecular design. Its structure was characterized by infrared spectroscopy and nuclear magnetic resonance H-spectrum. The performance evaluation results show that after the inhibitor is added, the subcooling degree decreases (- 8.1 ℃), and the induction time increases (27.8 min). Through density functional theory research, it is found that the carbon chain skeleton tends to provide electrons, while the ester group tends to receive electrons and react. After molecular dynamics simulation, it is found that the inhibitor can occupy the existing water molecule cage, and the increase of hydrogen bonds It indicates that it inhibits the formation of hydrates by preventing methane molecules from entering the water molecule cage through interaction. Finally, thermodynamic inhibitors and anti polymerization agents were screened and combined to obtain an inhibitor formula, which consisted of 10% methanol, 0.75% oleic acid betaine, and 0.75%PNVP/NVCL/BEM (the subcooling degree after addition is -13 ℃, and the induction time is 100.7 min), and its inhibitory effect reached that of 20% methanol. The usage of methanol has been significantly reduced to minimize the impact on the environment and the downstream ethylene production from ethane.