Abstract: Autofluorescence is the fluorescence naturally emitted by the internal tissue components of organisms when absorbing light, which will affect the effective recognition of artificial labeling fluorescence and seriously interfere with the observation and data analysis of the fluorescence of antibody labeled target protein, especially in the study of immunofluorescence labeling of coral frozen sections. In order to effectively remove the autofluorescence in the coral tissue slices, this study took the symbiotic model Xeniasp. as the research object, and for the first time tried to use a TrueBlack Lipofuscin autofluorescence quenching agent commonly used in mouse and human tissue slices in the immunofluorescence staining of frozen sections of Xeniasp., and compared it with the alcohol gradient dehydration method in existing studies. Results showed that TrueBlack Lipofuscin could more effectively remove the autofluorescence intensity as much as 52.4% compared with the alcohol gradient dehydration method in the tissue slices of Xeniasp., and the effect was the best under Cy5 channel. At the same time, antibody incubation and protein hybridization experiments proved that the use of autofluorescence quenching agent TrueBlack Lipofuscin did not affect coral immunofluorescence labeling. It showed that the specific fluorescence signal intensity was 205.3% of the control group, and the background fluorescence and autofluorescence were basically removed.