Abstract: The present invention belongs to the technical field of natural gas hydrates (NGHs), and provides an environmentally friendly NGH inhibitor and application. The hydrate inhibitor has a component of nisin, and further comprises chitooligosaccharide and an alcohol thermodynamic hydrate inhibitor, that can enhance the thermostability of the inhibitor and the inhibitory effect for NGHs. The optimal application conditions of the NGH inhibitor of the present invention are: temperatures of ?10 to 100° C., pressures of 0.1 to 25 MPa, and a maximum subcooling degree of 12° C. The inhibitor of the present invention has good NGH inhibitory performance and certain antibacterial effects, which is a low-dose, degradable, high temperature resistant, green, environmental protective, safe and efficient NGH inhibitor, that can be used for the fields of oil-gas transportation and NGHs, and provides a new solution for field application of green natural hydrate inhibitors.