In this numerical study, a 3D conjugate model of a microchannel of width (W) 1 mm, height (H) 0.63 mm, and length (L) 50 mm with the novel butterfly-wing vortex generator is considered. The entropy-generation analysis is studied by varying the inclination angle (α) of butterfly-wing from 0° to 7° and Reynolds number (Re) from 143 to 945. DI-water is considered as working fluid and a constant heat flux of 50000 W/m² is applied at the bottom and sidewalls of the microchannel. The simulation results show that with the increase in α value total entropy-generation (S_G) decreases compared to the plain microchannel. The maximum reduction of entropy generation value of 14% is achieved for α=7° at Re= 945.