The invention provides a gas hydrate generation promoter and a preparation method and application thereof. The gas hydrate generation promoter comprises, by 100wt% of total mass, 0.03-1wt% of nano graphite powder, 0.01-0.06wt% of alkyl diphenyl ether disulfonate and the balance of water. The nano graphite powder and alkyl diphenyl ether disulfonate are used to enhance mass transfer and heat transfer processes of hydrate, so that overall time for generating the hydrate can be shortened, and synthesis efficiency of the hydrate can be improved. The promoter can well adapt to existing hydrate generation systems and is high in adaptability to temperature-pressure conditions in hydration reaction. In addition, timely guide-out of heat can lower workload of a refrigerating system (water bath refrigerating and air cooling), so that running cost is low.