A light guide structure for a direct type backlight module, the light guide structure comprising: a first waveguide layer having a first light incident surface and a first light exiting surface; a polarization beam-splitting structure disposed on the first light exiting surface, and configured to split light emitted from a light source into a first polarized light and a second polarized light, wherein the first polarized light is reflected by the polarization beam-splitting structure 3 into the first waveguide layer 1, and the second polarized light passes through the polarization beam-splitting structure 3; a first polarization coupling grating disposed on the first light incident surface and configured to deflect the first polarized light and allow the first polarized light to be totally reflected in the first waveguide layer; a second polarization coupling grating disposed between the second light incident surface and the polarization beam-splitting structure; and a second waveguide layer having a second light incident surface and a second light exiting surface and disposed on the polarization beam-splitting structure, wherein the second polarization coupling grating is configured to deflect the second polarized light and allow the second polarized light to be totally reflected in the second waveguide layer and then emit from the second light exiting surface, wherein a first mesh layer is disposed at a position of the first light exiting surface where no polarization beam-splitting structure is provided and/or a position of the first light incident surface where no first polarization coupling grating is provided; and a second mesh layer is disposed at a position of the second light exiting surface and/or the second light incident surface where no second polarization coupling grating is provided. a first waveguide layer having a first light incident surface and a first light exiting surface; a polarization beam-splitting structure disposed on the first light exiting surface, and configured to split light emitted from a light source into a first polarized light and a second polarized light, wherein the first polarized light is reflected by the polarization beam-splitting structure 3 into the first waveguide layer 1, and the second polarized light passes through the polarization beam-splitting structure 3; a first polarization coupling grating disposed on the first light incident surface and configured to deflect the first polarized light and allow the first polarized light to be totally reflected in the first waveguide layer; a second polarization coupling grating disposed between the second light incident surface and the polarization beam-splitting structure; and a second waveguide layer having a second light incident surface and a second light exiting surface and disposed on the polarization beam-splitting structure, wherein the second polarization coupling grating is configured to deflect the second polarized light and allow the second polarized light to be totally reflected in the second waveguide layer and then emit from the second light exiting surface, wherein a first mesh layer is disposed at a position of the first light exiting surface where no polarization beam-splitting structure is provided and/or a position of the first light incident surface where no first polarization coupling grating is provided; and a second mesh layer is disposed at a position of the second light exiting surface and/or the second light incident surface where no second polarization coupling grating is provided. a first mesh layer is disposed at a position of the first light exiting surface where no polarization beam-splitting structure is provided and/or a position of the first light incident surface where no first polarization coupling grating is provided; and a second mesh layer is disposed at a position of the second light exiting surface and/or the second light incident surface where no second polarization coupling grating is provided.