A qubit assembly preparation method, performed by a production line device, the method comprising: respectively preparing a waveguide film 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 , the qubit structure comprising a three-layer structure, the three-layer structure comprising a first superconducting portion and a second superconducting portion intersecting with each other in a coverage region on the substrate , outer surfaces of the first superconducting portion and the second superconducting portion being respectively covered by an insulation layer , and the outer surfaces of the first superconducting portion and the second superconducting portion being separated from the substrate ; removing the insulation layer on a first target region of an upper surface of the first superconducting portion 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 and the second superconducting portion 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 and the second superconducting portion and facing the substrate ; and evaporating a connection layer on the waveguide film , the qubit structure, and the substrate between the waveguide film and the qubit structure , to obtain the qubit assembly, the connection layer being configured to respectively communicate the first superconducting portion and the second superconducting portion with the waveguide film in different regions, characterised by a side surface of the waveguide film being an oblique surface extending outward from a top region. respectively preparing a waveguide film 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 , the qubit structure comprising a three-layer structure, the three-layer structure comprising a first superconducting portion and a second superconducting portion intersecting with each other in a coverage region on the substrate , outer surfaces of the first superconducting portion and the second superconducting portion being respectively covered by an insulation layer , and the outer surfaces of the first superconducting portion and the second superconducting portion being separated from the substrate ; removing the insulation layer on a first target region of an upper surface of the first superconducting portion 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 and the second superconducting portion 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 and the second superconducting portion and facing the substrate ; and evaporating a connection layer on the waveguide film , the qubit structure, and the substrate between the waveguide film and the qubit structure , to obtain the qubit assembly, the connection layer being configured to respectively communicate the first superconducting portion and the second superconducting portion with the waveguide film in different regions, characterised by a side surface of the waveguide film being an oblique surface extending outward from a top region. <EOS>