A qubit assembly preparation method, performed by a production line device, the method comprising: respectively preparing a waveguide film (62, 1402) in at least two regions on a substrate spaced apart from each other, preparing, by using a Dolan bridge photoresist structure, a qubit structure separated from the waveguide film (62, 1402), the qubit structure comprising a three-layer structure, the three-layer structure comprising a first superconducting portion (63a, 1403a) and a second superconducting portion (63c, 1403b) intersecting with each other in a coverage region on the substrate, outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) being respectively covered by an insulation layer, and the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) being separated from the substrate; removing the insulation layer on a first target region of an upper surface of the first superconducting portion (63a, 1403a) and the insulation layer on a second target region of an upper surface of the second superconducting portion, the upper surface being a surface in the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) and being on a side opposite to a lower surface, and the lower surface being a surface in the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) and facing the substrate; and evaporating a connection layer (64, 65) on the waveguide film (62, 1402), the qubit structure, and the substrate between the waveguide film (62, 1402) and the qubit structure, to obtain the qubit assembly, the connection layer (64, 65) being configured to respectively communicate the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) with the waveguide film (62, 1402) in different regions, characterised by a side surface of the waveguide film (62, 1402) being an oblique surface extending outward from a top region. respectively preparing a waveguide film (62, 1402) in at least two regions on a substrate spaced apart from each other, preparing, by using a Dolan bridge photoresist structure, a qubit structure separated from the waveguide film (62, 1402), the qubit structure comprising a three-layer structure, the three-layer structure comprising a first superconducting portion (63a, 1403a) and a second superconducting portion (63c, 1403b) intersecting with each other in a coverage region on the substrate, outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) being respectively covered by an insulation layer, and the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) being separated from the substrate; removing the insulation layer on a first target region of an upper surface of the first superconducting portion (63a, 1403a) and the insulation layer on a second target region of an upper surface of the second superconducting portion, the upper surface being a surface in the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) and being on a side opposite to a lower surface, and the lower surface being a surface in the outer surfaces of the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) and facing the substrate; and evaporating a connection layer (64, 65) on the waveguide film (62, 1402), the qubit structure, and the substrate between the waveguide film (62, 1402) and the qubit structure, to obtain the qubit assembly, the connection layer (64, 65) being configured to respectively communicate the first superconducting portion (63a, 1403a) and the second superconducting portion (63c, 1403b) with the waveguide film (62, 1402) in different regions, characterised by a side surface of the waveguide film (62, 1402) being an oblique surface extending outward from a top region.