A perfluorohexanone microcapsule with a high core-wall ratio is provided. In the perfluorohexanone microcapsule, there is no need for auxiliary materials/fillers and other adsorption or high-boiling solvent to dissolve perfluorohexanone. By coating the microcapsule shell with secondary polymers, the shell strength of the microcapsule is improved, the volatilization loss of perfluorohexanone is reduced, and the problem of short storage life of the perfluorohexanone microcapsule material is overcome, so that it has commercial application value. The perfluorohexanone microcapsule can be further compounded with various materials and interfaces to obtain various fire extinguishing materials with perfluorohexanone microcapsule as the core component. This kind of fire extinguishing material can be dry powder of perfluorohexanone microcapsules, and can also be made into shapes suitable for various surfaces, such as fire extinguishing stickers, fire extinguishing blankets and fire-fighting clothes with various thicknesses.