We investigate the electronic transport properties of a molecular motor as an optical molecular switch by using the non-equilibrium Green's function formalism combined with first-principles density functional theory. The two main forms of this molecule during the 360 rotation, named the anti-folded isomer and the syn-folded isomer, have shown a consistent difference in the current. The current of the syn-folded isomer is larger than that of the anti-folded isomer, meaning that the conductivity of the molecules alters four times within a rotary cycle. The merit of the photo-induced conductivity tuning makes the molecule a promising candidate for optical molecular switches. (C) 2017 Elsevier B.V. All rights reserved.