The present disclosure relates to the transformed Synechococcus elongatus strain of capable of mass production of farnesene. The transformed Synechococcus elongatus strain of the present disclosure is characterized by having the ability to mass produce farnesene using carbon dioxide as an independent carbon source. In particular, the Synechococcus elongatus strain is economically effective because it uses carbon dioxide present in light and air as a carbon source. There is an eco-friendly effect since it can be used for eliminating or reducing carbon dioxide in the atmosphere using microorganisms. Further, the strain of the present disclosure has a rapid growth rate and excellent ability to fix carbon dioxide compared with other microorganisms, thereby being utilized in various fields such as food, medicine, pharmacy, biofuel, and chemistry.