The invention relates to the technical field of immunoassay, and especially relates to a fluorescence immunoassay method of procalcitonin in saliva. A saliva collector, saliva, an anti-procalcitonin antibody, a fluorescence reagent and a detector are used in the invention. The saliva collector comprises one or a combination of a collecting tube, a collecting rod and a collecting scraper sheet; the anti-procalcitonin antibody is one or a combination of an anti-procalcitonin monoclonal antibody and an anti-procalcitonin polyclonal antibody; the fluorescence reagent is a liquid phase and/or solid phase material containing a fluorescent substance, and the fluorescent substance is one or a combination of organic fluorescence dyes or rare earth element fluorescence dyes; and the detector is a fluorescence detector. The method adopting human body saliva as a detection sample has the advantages of effective monitoring of procalcitonin in saliva, strong specificity, good repeatability, high sensitivity, simplicity in operation, no special devices, no professional training, clear and distinguishable result, easiness in promotion, and suitableness for onsite detection.