Environmental DNA（eDNA）was a qualitative or quantitative analysis method conducted with molecular biology and sequencing technology，after DNA was directly extracted from environmental samples（soil，sediment，water，biofilm，etc.），which was characterized by low cost，high efficiency and non-invasive sampling，and had been widely used in the researches on species diversity of ecological system，the detection of resource biomass，endangered and invasive species. In recent years，the method had been rapidly applied in the detection of pathogens in aquatic animals，especially in monitoring the diseases of animals with high value and the rare ones. In the paper，the researches on the application of eDNA in aquatic animal disease monitoring were reviewed，the limitations of eDNA were mentioned，although it could be used to sample aquatic animals under different conditions，which was contributive to the active surveillance for aquatic animal diseases. A reference was thus provided for further application of eDNA in aquatic animal disease monitoring.