Surface texturing of silicon can reduce the reflectance of incident light and increase the conversion efficiency of solar cells. Many approaches have been present in texturing silicon solar cell. In this paper, ultrasound is introduced into acid solution to texture the surface of multicrystalline silicon (mc-Si) solar cell. The morphology images are obtained by scanning electron microscope (SEM), more holes and regular distributed morphology for the presented method can be observed. Antireflectance of the mc-Si surface is measured by spectrophotometer, and the reflectance of 10.2% is obtained for the presented method, which is much less than that of acid etching.