A light source module, comprising an optical waveguide structure, a first light source, a second light source and a third light source, and a pre-collimating optical element, wherein the optical waveguide structure comprises a light introduction part and a main body part which are provided in parallel in a first direction, the light introduction part comprises a light incident surface, and the main body part comprises a light emitting surface; the first light source is opposite to the light introduction part in the first direction, and is configured to provide first light; the second light source and the third light source are both opposite to the light incident surface, and are respectively configured to provide second light and third light; and the pre-collimating optical element is provided between the first light source and the light introduction part in the first direction, and is configured to collimate at least a portion of the first light to be first collimated light, and to collimate at least a portion of the second light to be second collimated light and to collimate at least a portion of the third light to be third collimated light, respectively, wherein the light introduction part is configured to introduce at least a portion of the first collimated light, which is incident from the light incident surface, into the main body part at a first angle (γ1) with respect to the light emitting surface to satisfy a total reflection condition of the main body part, characterized in that, a wavelength λ1 of the first light, a distance a1 between the first light source and a second projection plane, a wavelength λ2 of the second light, a wavelength λ3 of the third light, a distance a2 between the second light source and the second projection plane, a distance a3 between the third light source and the second projection plane satisfy following relationships: λ1<λ2<λ3, and a1> a2> a3; and the second projection plane is parallel to the light emitting surface, and a main optical axis of the pre-collimating optical element is in the second projection plane, wherein in the case where the light source is located on the side of the second projection plane close to the light emitting surface, the distance between the light source and the second projection plane is set to a positive value, and in the case where the light source is located on the side of the second projection plane away from the light emitting surface, the distance between the light source and the second projection plane is set to a negative value. wherein the optical waveguide structure comprises a light introduction part and a main body part which are provided in parallel in a first direction, the light introduction part comprises a light incident surface, and the main body part comprises a light emitting surface; the first light source is opposite to the light introduction part in the first direction, and is configured to provide first light; the second light source and the third light source are both opposite to the light incident surface, and are respectively configured to provide second light and third light; and the pre-collimating optical element is provided between the first light source and the light introduction part in the first direction, and is configured to collimate at least a portion of the first light to be first collimated light, and to collimate at least a portion of the second light to be second collimated light and to collimate at least a portion of the third light to be third collimated light, respectively, wherein the light introduction part is configured to introduce at least a portion of the first collimated light, which is incident from the light incident surface, into the main body part at a first angle (γ1) with respect to the light emitting surface to satisfy a total reflection condition of the main body part, characterized in that, a wavelength λ1 of the first light, a distance a1 between the first light source and a second projection plane, a wavelength λ2 of the second light, a wavelength λ3 of the third light, a distance a2 between the second light source and the second projection plane, a distance a3 between the third light source and the second projection plane satisfy following relationships: λ1<λ2<λ3, and a1> a2> a3; and the second projection plane is parallel to the light emitting surface, and a main optical axis of the pre-collimating optical element is in the second projection plane,