The invention discloses a multi-response azacyclic 
formaldehyde fluorescent probe molecule with the structure shown in formula I and its preparation method and application. The molecule realizes the selective and quantitative recognition of 
formaldehyde through the 
fluorescence analysis method, and is used in automotive interior materials, health  Carry out testing and evaluation of 
formaldehyde, 
copper ions and 
sulfide ions in the fields of home furnishing, 
biomedicine, etc. It can also be used for 
fluorescence imaging of biological samples, and can also be used as an 
ultraviolet absorber for plastics, coatings, inks, displays, lighting, glasses, daily use  
Chemical industry, textiles and other technical fields, in addition, the multi-responsive azacyclic formaldehyde fluorescent probe molecule provided by the present invention has strong 
fluorescence emission performance in solution and 
solid state, and can be used as a fluorescent material for anti-counterfeiting technology, light conversion  Materials, fluorescent labels, 
fluorescent imaging, etc.: wherein, R is H or Cl, and X is CH or N.