The invention discloses an artemisia apiacea bHLH transcription factor as well as an encoding gene and an application thereof. The artemisia apiacea bHLH transcription factor provided by the invention is protein shown as a) or b): a) protein which consists of amino acid sequences and is shown in sequences 2 in a sequence table; and b) protein which is derived from a), is formed through substituting and/or deleting and/or adding amino acid sequences shown by the sequences 2 in the sequence table through one or a plurality of amino acid residues and is relevant to the artemisinin synthesis. The bHLH transcription factor is instantaneously translated into artemisia apiacea plants to be overexpressed, the expression quantity of the key enzyme in regulated and controlled artemisinin biosynthetic metabolism is greatly improved, and the artemisia apiacea bHLH transcription factor can be used for producing artemisinin. The regulated and controlled artemisinin synthesis method solves the problem of raw material limitation, has a simple production process and is favorable for the large-scale industrial production of the artemisinin.