The invention provides a fluorescence chemical sensor for detecting 2,4,6-trinitrophenol and a preparation method of the fluorescence chemical reactor, belonging to the technical field of preparation and chemical analysis of functional high polymer materials. The fluorescence chemical sensor has a chemical structure shown in the specification. The preparation method of the fluorescence chemical sensor comprises the following steps: (1), in the presence of an acid-binding agent, performing condensation polymerization in an organic solvent by using phosphonitrilic chloride trimerl and curcumin to obtain a solution; (2), separating a solid product in the solution, washing and drying to obtain the fluorescence chemical sensor. The fluorescence chemical sensor based on ring-crosslinking type polyphosphazene, disclosed by the invention, is simple and mild in preparation process, has excellent thermal stability, chemical stability and fluorescence characteristics, can be used for realizing specific identification and detection of 2,4,6-trinitrophenol in a liquid phase, is high in sensibility, is suitable for the fields of trace explosive detection and environment monitoring, and is favorable for realizing industrial production.