A gene sequence construct used for the treatment of central nervous system diseases: by means of the construction of an auto-processing expression vector, tyrosine hydroxylase (TH), GTP-cyclohydrolase I (GCH1), aromatic amino acid dopa decarboxylase (AADC), and so on may be simultaneously expressed; proteins are connected by means of an auto-processing unit (APU); the use of a viral vector to introduce the construct into a target cell may ultimately result in the high-efficiency expression of tyrosine hydroxylase (TH), GTP-cyclohydrolase I (GCH1), aromatic amino acid dopa decarboxylase (AADC), and so on having independent functions, being used in the prevention or treatment of Parkinson's disease, Alzheimer's disease and other neurodegenerative diseases.