The invention relates to a design method used for transmitting DC high-temperature superconducting cable body coaxially and bidirectionally, belonging to the field of power
system transmission and transformation; the design method comprises the steps as follows: according to the mechanical characteristic and the
radius of enwinding framework of the superconducting strips, parameters of the superconducting cable body such as the enwinding
helix angle and the enwinding
pitch are determined; the
magnetic field distribution of all
layers of superconducting cable body are determined according to the operation current, thus determining the
critical current on all
layers of the cable; according to the
critical current and the operation redundancy, iterative calculation is carried out for operation current and the
magnetic field, thus finally gaining the
critical current, best operation current, enwinding layer number and number of the cables. The designed superconducting cable body increases no enwinding process difficulty and achieves
bidirectional transmission of
DC current; the utilization ratio of the superconducting strip critical current reaches more than 90%; the quantity and low-temperature heat loss of the superconducting cable low-temperature container are respectively reduced by half. The design method has the advantages of large transmission capability, no loss, compact structure, certain
current limiting capability, stable mechanical structure, self-shielding, no
electromagnetic interference and the like.