The pathogenic fungi causing the rot disease of postharvest chestnut were isolated and purified by tissue separation method to clarify the predominant pathogenic fungi of postharvest chestnut and the control effect of plant essential oil on them.Further morphological and molecular biological identification of the predominant pathogenic fungi was carried out by microscopic observation and double-gene phylogenetic analysis.On this basis， the control effect of a single component of 10 plant essential oils including perillaldehyde， cinnamaldehyde， citral， folic aldehyde， eugenol， linalool， nerol， thymol， carvacrol， and citronellol on the predominant pathogenic fungi in chestnut postharvest was analyzed.The results showed that the predominant rot-causing fungi of postharvest chestnut included Fusarium sp.， Neofusicoccum sp.， Geotrichum sp. and Mucor sp.， among which strains BL-8 and BL-18 were identified as Fusarium asiaticum and Neofusicoccum parvum by double-gene phylogenetic analysis.The single component of 10 plant essential oils had a certain degree of inhibitory effect on the predominant rot-causing fungus strain BL-8 and BL-18 of postharvest chestnut.Among them， carvacrol had the most obvious antifungal activity against the predominant pathogenic fungi of postharvest chestnut， with its EC₉₀ value on the strain BL-8 and BL-18 of 24.431 μL/L and 11.768 μL/L， respectively.It was further found that carvacrol significantly inhibited the growth of the two predominant pathogenic fungi through in vitro pathogen growth inhibition test and natural storage test.Carvacrol fumigation treatment effectively controlled the occurrence of disease in postharvest chestnut caused by the infection of strain BL-8 and BL-18.Therefore， carvacrol as a fumigant has potential application value in controlling fungal diseases of postharvest chestnut.