The chemical cracking effect on metallurgical-grade silicon (MG-Si) during leaching by aqua regia was investigated. The results showed that the granularity of the particles was reduce by acid leaching, and the phenomenon was more noticeable with the increase in the silicon particle size. The cracking was essentially ascribed to the dissolution of the major impurities that depended on the composition and distribution of the impurity phases in MG-Si. In addition, the removal efficiency of the main metallic impurities with the occurrence of the chemical cracking effect during the leaching process was studied. The remarkable efficiency was obtained from the coarse particle size,where 7.9% Fe, 77% Al, 45% Ca, and 63% were removed. The reason could be attributed to the strong oxidation of aqua regia that promoted the dissolution Of the Si Al-Fe soluble phase, which resulted in the enhanced removal effect of acid on the impurities.