Provided is an optically controlled gene expression system, comprising: a) a photosensitive recombinant transcription factor encodes a gene, the photosensitive recombinant transcription factor comprising a first polypeptide as the DNA bonding domain, a second polypeptide as the photosensitive domain, and a third polypeptide as the transcription regulatory domain； b) a target transcription unit comprising at least one reaction element identified and bound by the first polypeptide, and a promoter and a nucleotide sequence to be transcribed regulated by the third polypeptide. Also provided is a eukaryotic expression vector comprising said optically controlled gene expression system, and a method for regulating gene expression in a host cell by using the optically controlled gene expression system. Also provided is a reagent kit containing different components of the optically controlled gene expression system. The optically controlled gene expression system has a quick, effective and powerful induction, is safer than other inducers, is of little or no toxicity, and can control gene expression both spatially and temporally.
