Abstract: This paper deals with the effect of digestion conditions on pre-treatment of woody activated carbon by microwave digestion method. The results showed that the critical factors on digestion reaction are digestion temperature, digestion time and digestion acid system. Different size of granulate activated carbon can be digested completely under microwave energy with acid system of 8 mL(6 mL HNO3+1 mL H2O2+1 mL HF) at 220℃ for 30 min. It was found that different kinds of woody activated carbons could be digested by higher temperature, expanding digestion time and increasing dosage of acid.