The invention discloses a method for regulating the content of starch in a corn kernel based on a ZmMIKC2a gene and belongs to the technical field of gene engineering. The method comprises the following steps: I) constructing a ZmMIKC2a gene over-expression vector to obtain a ZmMIKC2a gene over-expression plant; II) knocking out the ZmMIKC2a gene in a target corn to obtain a ZmMIKC2a gene deletion plant. The method disclosed by the invention has the advantages that the positive regulation effect of the ZmMIKC2a gene on corn kernel starch synthesis related genes is utilized; the content of amylose in the target corn and the ratio of the amylase to total starch are improved or reduced through a gene engineering method, so that a new transgenic corn variety with high amylose, low amylopectin or high amylopectin/low amylose is obtained; the method is of great practical significance in developing the new transgenic corn variety with a specific function by utilizing a gene engineering technology.