The coupling acoustic matching is investigated to realize acoustic sensors with a microfluidic channel, in which two overlap layers couple three local quarter-wavelength transmission elements. Provided that the reflecting waves from both sides of each overlap layer satisfy destructive interferences, most acoustic energy can be transmitted. Especially, the microfluidic channel is sensitive to realize a function of the acoustic matching, which could induce effects of an approximate half-wavelength transmission and much acoustic dissipation. With an optimized design, the detections of liquid properties with a high quality factor 300 in liquid environment, and a mass sensitivity of 95 kHz mm2/ng are obtained.