Micromixing plays a significant role in microfluidics. Here a passive mixer with triangle baffles embedded in the main channel was designed, fabricated and characterized. Systematic simulations and experiments have been done with the increase of Reynolds number (Re), ranging from 0.1 to 500. All results confirmed the improvement of mixing within a short distance (<6.4 mm). At common flow rate of microfluidics (Re = 1.0), 'the percentage of mixing' (φ) can be 85.5% by the distance of 6.4 mm, which is 2.48-fold better than that of common Y-mixer. φ values of the design containing triangle baffles are 4.75-time at Re of 100 and 8.32-time at Re of 500 better than those of the common Y-mixer at the distance of 6.4 mm, respectively. The mixing effect caused by different apical angle and the number of triangles was also investigated using simulations. The mixing effect was improved with the growth of the apical angle of the triangles from 30 to 150°. Similarly, more triangle baffles lead to better mixing effect.