The sodium iron chlorophyllin by the chlorophyl form Sonchus oleraceus L was obtained through the following successive steps: saponificatioan,acidification,replacement of sodium by iron,and neutalization.Its quality was evaluated by UV-spectrophotometer.Single factor experiment and response surface method in optimization of process test conditions: Firstly,chlorophyl is saponifieated for 90min at 59℃ in the system with pH≈12;Secondly,the saponificated production is acidificated for 60min at 65℃ in the system with pH≈2~3;And afterword replaces sodium with 42mL 10%FeSO_4 for 97min.Finally,the sodium iron chlorophyllin is obtained by neutralizing at pH≈12 with 10%NaOH-ethanol.