With the activated carbon iodine adsorption and yield as the optimization index, the process of Suaeda sasla carbon taking H₃PO₄-ZnCl₂ as the dual activator was studied. The single-factor test was used to examine the effect of mass fraction of H₃PO₄-ZnCl₂, activation temperature, and the activation time on activated carbon preparation. The optimum conditions for the preparation of S. sasla based activated carbon by orthogonal experiments were as follows: H₃PO₄-ZnCl₂ mass fraction 30%, activation temperature 500 ℃, activation time 80 min. Under these conditions, the iodine adsorption value and yield of the Suaeda carbons were 865.45 mg/g and 43.39%。