A waveguide structure is provided. A silicon substrate layer, a silicon waveguide layer, a first silicon dioxide layer, a silicide waveguide layer, and a second silicon dioxide layer are stacked in sequence, the silicon waveguide layer is a conical waveguide layer, the silicon waveguide layer and the silicide waveguide layer are coupled by using an evanescent wave, the silicide waveguide layer includes multiple first waveguide blocks and multiple second waveguide blocks, a material of the first waveguide blocks is the same as a material of the silicide waveguide layer, and a refractive index of a material of the second waveguide blocks is lower than a refractive index of the material of the first waveguide blocks. By using the waveguide structure, a waveguide flare size can be increased, so as to match a mode size of a fiber core of an optical fiber.