Using natural corn starch as raw material， the high pressure porous starch was prepared by the combination of high static pressure， α-amylase and saccharase. The porous starch was cross-linked with sodium trimetaphosphate and optimized. The structure and physicochemical properties of the cross-linked porous starch were studied. The results show that when the pressure is 200 MPa， both the high pressure porous starch and the high pressure cross-linked porous starch have good porous starch morphology， the high pressure cross-linked porous starch particle pore structure is more uniform， the specific surface area and pore size are increased obviously， the short-range ordered structure is destroyed， the crystallinity is reduced， and at the same time. The porous structure of high pressure cross-linked porous starch improved the adsorption， and the oil absorption and water absorption increased from 68% and 120% to 75% and 124%， respectively. The optimum conditions for preparation of porous starch were determined as follows: temperature 40 ℃， reaction pH 11， dosage of crosslinking agent 3% of starch base， pressure 200 MPa， and deposition volume measured in single factor and orthogonal experiments. The light transmittance of high pressure cross-linked porous starch prepared by this process decreased by 3.26% and 5.06%， respectively， compared with that of porous starch and high pressure porous starch. Compared with porous starch and high pressure porous starch， the water separation rate decreased by 24.7% and 28.5%， respectively. The solubility and swelling degree of porous starch formed under different treatment conditions are significantly higher than that of original starch， which is beneficial to the application of porous starch.