The invention discloses carbon skeleton enhanced porous starch and a preparation method thereof. The preparation method of the porous starch includes the steps that starch and transition metal ions are bonded, then the starch to which the transition metal ions adhere and amylase are treated through extrusion equipment, and finally a high-strength recombined-structure starch-based porous material,namely the carbon skeleton enhanced porous starch is formed. The enzyme dosage of a biological method is reduced, the action time of the biological method is shortened, the current situation that a physical method can only serve as pretreatment is also changed, and the carbon skeleton enhanced porous starch and the preparation method thereof have wide application prospects in the fields of medicine controlled release, water pollution purification, embedded and alternative targets and other fields of medical treatment, chemical engineering, environments and materials.