To explore the potential of acid leaching in purification metallurgical grade silicon (MG-Si) for solar cells, the effect of acetic acid on the leaching behavior was investigated in the present work by focusing on the behavior of impurities affected by the addition of acetic acid to a conventional acid mixture composed of hydrochloric acid and hydrofluoric acid. The etching results reveal that the HCl-HF-CH3COOH mixture is a better lixiviant for dissolving impurity inclusions in MG-Si. The extraction yield of impurities in HCl-HF-CH3COOH leaching was found to increase by 7% compared to conventional HCl-HF leaching.