The invention discloses a preparation method of a lightweight high-stability MgB2 multi-core
superconducting wire. The method comprises the following steps: 1, loading an Al2O3-Al rod into a Cu tube, and
processing to obtain a reinforced core; 2, putting the Mg
powder / rod and the B
powder precursor into an Nb tube, putting the Nb tube into a Cu tube, and
processing to obtain a
single core wire; 3, inserting the reinforced core and the single-core wire into the composite sheath which is filled into the Al2O3-Al tube from the
Monel tube to obtain a secondary composite tube body; 4,
processing the secondary composite tube body into a
wire rod; and 5, performing phase heat treatment on the wire. According to the invention, the low-density nano Al2O3 reinforced aluminum-based
composite material is adopted to partially replace a high-density
metal sheath and optimize the Al2O3-Al area proportion, so that the weight of the wire is reduced, and the electrical-thermal-mechanical comprehensive stability of the MgB2
superconducting wire is synergistically improved by utilizing the excellent mechanical, electrical and
thermal conductivity of the
composite material; and the requirements of light weight and high stability of the
aviation-level superconducting motor are met.