The present study aimed at investigating the alum-processing mechanism attenuating toxicity of Araceae Pinellia ternata and Pinellia pedatisecta. Animal retroperitoneal inflammatory model in vivo and macrophagocyte release inflammatory factor model in vitro were used to detect the effect of alum processing on raphides and lectin. Scanning electron microscopy was used to observe the change in raphides during processing; HPLC method was used to determine the correlation between the dissolution and corrosion of raphides and ion in the alum solution; (27)Al-NMR technology was used to detect the relationship between aluminum oxalate complex formation and the dissolved and corrosion of raphides. The change in protein peptide sequence of lectin during the processing of alum solution was determined by Shotgun LC-MS assay. Raphides induced severe rabbit conjunctival edema and an intraperitoneal injection of lectin increased PGE2 and protein in mice peritoneal exudate, while decreased after treatment with alum solution processing. During the processing raphides was dissolved and corroded, then its structure was damaged. Raphides was soaked in the alum solution and significantly decreased the oxalate content, and the effect was related with Al(3+) in the alum. Al(3+) in the alum combined with C2O4(2-) of raphides into a stable complex compound promoted the dissolution of calcium oxalate. Raphides soaked in the alum made lectin proteins dissolve, whereas protein peptide sequence of lectin was changed and the protein structure was damaged. Alum solution could decrease the toxicity of P. ternata (Thunb.) Breit. and P. pedatisecta Schott. Since it made a special crystal structure of raphides damage and the protein of lectin dissolve. The structure of toxic substances significantly changed, which decreased the inflammatory effect.