An optical waveguide structure. A waveguide core region consists of inner and outer layers (1, 2) having different refractive indices; the refractive index ratio of materials having different refractive indices is greater than or equal to 1.15. A dispersion control method using the optical waveguide structure comprises: first, obtaining a dispersion curve having a maximum of five dispersion zero points by calculation according to a set of preset structural size parameters of an optical waveguide; and then, adjusting one or more of the width (W) of a contact surface between the inner layer (1) and the base (3), the thickness (H) of a high refractive index material, and the thickness (C) of a low refractive index material, so as to implement dispersion control. The core region of the waveguide structure is changed into the inner and outer layers (1, 2), and the outer layer (2) does not need to be etched, so that the processing steps required for the dispersion control of the waveguide is reduced, and the requirements of processing conditions are reduced. Moreover, the waveguide structure can generate up to five dispersion zero points, and the resultant flat dispersion bandwidth exceeds two octaves.