The invention discloses a preparing method of a nonmagnetic high-strength textured Cu-base ternary alloy base band. Vacuum induction melting is conducted on copper blocks and nickel blocks to obtain a CuNi binary alloy ingot, wherein the atomic percent of Cu is 54%-60%, then the Cu-Ni ingot and a vitriol block are placed in an electro-magnetic induction vacuum melting furnace to be melted to obtain a Cu-Ni-V ternary alloy ingot, and the atomic percent of the V is 4%-9%; then, after 1-2 hours of heat insulation of the ternary alloy ingot is conducted at the temperature of 850-950 DEG C, hot forging and hot rolling are conducted on the ternary alloy ingot to form billet, and cold rolling processing is conducted on the billet after hot rolling; at last, recrystallization heat treatment is conducted on a cold rolling base band under the protection of Ar/H2 mixed gas, the temperature is improved to 1000-1050 DEG C with the heating rate being of 10-15 DEG C/min, and heat insulation is conducted for 30-60min. The obtained textured Cu-base ternary alloy base band has high mechanical strength and a sharp cube texture, and does not have magnetism in a liquid nitrogen temperature zone.