Abstract: A method for determining the type of a nucleotide on a nucleic acid sequence to be analyzed, and a nucleic acid sequencing method. In the method, at least one modified nucleotide for nucleic acid synthesis is separated from a nucleic acid sequence to be analyzed and other components on both sides of a membrane; when the modified nucleotide is transferred to the other side of the membrane under the action of an electric field by means of a nanopore embedded on the membrane, a synthesis reaction is conducted; moreover, the type of a base of the nucleotide is determined according to the change of the electrical properties of the nanopore in the process of the modified nucleotide is transferred by the nanopore, so as to implement sequencing.