Abstract:[Objective] An intracellular persistence model of light chain of botulinum toxin type A was established to simulate long-term poisoning caused by botulinum toxin type A. [Methods] The recombinant plasmid pcDNA3.1-ALC-GFP was designed and constructed, the plasmid was extracted for PCR verification, and transfected into Nureo-2a cells for expression. Western Blot and cell immunofluorescence analysis were used to verify the expression of ALC-GFP and its long-term persistence in cells. An intracellular persistence model of light chain of botulinum toxin type A was established, and the model was used for the screening of anti-botulinum toxin drugs. [Results] The recombinant plasmid pCDNA3.1-ALC-GFP was successfully constructed and transfected into Nureo-2a cells, which verified the long-term persistence of ALC-GFP in cells. The intracellular persistence model of light chain of botulinum toxin type A was successfully established, and the potential anti-botulinum drug CB3 of botulinum toxin type A was screened by this model. [Conclusions] The intracellular persistence model of light chain of botulinum toxin type A was successfully established and applied to the screening of CS1, CE2 and CB3 drugs, which laid a foundation for the study of detoxification of botulinum toxin A long-term poisoning.