A method for extended depth-of-field three-dimensional nanoscale-resolution imaging, which is applicable to the technical field of microscopic imaging, comprises the following steps: building an optical component having a double-helix point spread function and defocusing grating multistage imaging properties; performing imaging of a molecule to be detected by the optical component to obtain a double-helix image; determining a horizontal position of the molecule to be detected according to positions of middle points of double-helix sidelobes in the double-helix image; and determining an axial position of the molecule to be detected according to a rotation angle of a connection line of centers of the double-helix sidelobes in the double-helix image, and the positions of the middle points of the double-helix sidelobes. By combining the double effects of the double-helix point spread function and the defocusing grating multistage imaging, the method extends the depth of field and improves the resolution ratio. The method can be used for dynamic range imaging of subcellular fractions having any depth values in a whole cell, can produce dynamic function images of multiple moving molecules, and is of great significance to high-level understanding of the rule and relationship between subcellular structures and changes in cell function.
METHOD, OPTICAL COMPONENT AND SYSTEM FOR EXTENDED DEPTH-OF-FIELD THREE-DIMENSIONAL NANOSCALE-RESOLUTION IMAGING