Droplet fusion technology is a key technology for many droplet-based biochemical medical applications. By integrating a symmetrical flow channel structure, we demonstrate an acoustics-controlled fusion method of microdroplets using surface acoustic waves. Different kinds of microdroplets can be staggered and ordered in the symmetrical flow channel, proving the good arrangement effect of the microfluidic chip. This method can realize not only the effective fusion of microbubbles but also the effective fusion of microdroplets of different sizes without any modification. Further, we investigate the influence of the input frequency and peak-to-peak value of the driving voltage on microdroplets fusion, giving the effective fusion parameter conditions of microdroplets. Finally, this method is successfully used in the preparation of hydrogel microspheres, offering a new platform for the synthesis of hydrogel microspheres.