Abstract: As a new-type separation technology, the hydrate gas separation enjoys many advantages, but its application is restricted due to high generation pressure of hydrate, poor separation efficiency, and low generation rate of hydrate and so on, and special additives can improve hydrate separation performance. This paper summarizes additive types at home and abroad and the research progress in assessment methods and promotion principle of hydrate growth, and proposes future research direction, including search for an additive that is fully new, and does not involve generation of hydrate or occupies less hydrate cavities, which can make great improvement in phase equilibrium, separation efficiency and dynamic characteristics, carrying out effective complex formulation, and selecting optimum combination and addition volume of additives through experimental study of composite additive, applying precision measurement means to analyze the influence of surfactant on hydrate growth dynamics and verifying the promoting mechanism hypothesis and developing optimization and economical assessment of hydrate separation process flow containing an additive system.