The invention relates to the technical field of biopsy of intracellular carbohydrate chain antigen, specifically to a two-photon fluorescent probe, a fluorescence-labeled kit and a detection method used for biopsy of intracellular carbohydrate chain antigen. According to the invention, a two-photon fluorescence labeled antibody LP-IgG and a nitrocellulose-membrane-coated solid-phase antibody Ab are used; during detection, the solid-phase antibody specifically captures to-be-detected antigen through antigen reaction, so an immune complex Ab-Ag is formed; and the two-photon fluorescence labeled antibody LP-IgG is added and fully reacts with the immune complex (LP-IgG.Ab.Ag), then non-specific substances are washed and removed, and results can be detected and determined. The detection method provided by the invention overcomes the disadvantages of poor sensitivity and stability and complicated operation steps in a traditional detection method for carbohydrate antigen; meanwhile, detection samples are no longer limited to blood and peripheral blood, and any sample with carbohydrate chain antigen can be detected by using the kit prepared from the two-photon fluorescence-labeled probe LP.