The invention discloses a preparation method of canned corn. The method comprises the following steps: pre-cooling corn, carrying out microwave blanching, adding xanthan gum, sodium alginate and konjac gum compound gum, combining optimized ultrahigh-pressure sterilization with streptococcus lactis to prepare the new canned corn. The quality of sweet corn is improved by researching a vacuum rapid pre-cooling process of the sweet corn and different enzyme inactivation methods by heat, microwaves, steam and the like of the sweet corn; and by researching a boiling water blanching process, a steamblanching process and a microwave blanching process of the sweet corn kernels, the invention develops a technical process of the soft packaged canned sweet corn by combining the optimized ultrahigh-pressure sterilization with preservatives such as nisin and dimethyl dicarbonate, the influence of storage conditions on the shelf life and the quality of the canned sweet corn kernels is researched, and the canned corn which keeps the original fresh and sweet flavor, improves the grain feeling of residues and has a better taste is developed.