To achieve a high integration of fluorescence, conductivity and magnetism in the yarn structure while completely avoiding direct contact of different functional substances, three types of nanofibers with different functions are integrated into a yarn to achieve enhanced perovskite quantum dots (PQDs) fluorescence, intensified conductivity and adjustable magnetism. As a case study, [CsPbBr3 PQDs/polyacrylonitrile (PAN)]//[CoFe2O4/PAN]//[polyaniline (PANI)/PAN] triple-strand nanofibers yarns (TSNYs) were innovatively designed and constructed. We also advance a facile triple-strand conjugate electrospinning technology for the first time to create this specialized nanofiber yarn. The mechanical properties of the TSNYs are controllable by adjusting the twist. TSNYs emit strong green fluorescence excited by 365-nm ultraviolet (UV) light. The magnetism and conductivity of TSNYs are respectively tunable by regulating the contents of CoFe2O4 MNPs and PANI. With the aid of the peculiar structure of TSNYs, various substances are evenly distributed in the respective nanofibers avoiding direct contact. TSNY effectively prevents the adverse effects of dark-colored magnetic and conductive substances on the fluorescent properties, and the decrease in conductivity caused by mixing insulating substances with PANI is also avoided. TSNYs exhibit 33 times higher fluorescence intensity and two orders of magnitude higher conductivity than the composite nanofibers yarns. The formation mechanism of the TSNYs is elucidated, and triple-strand conjugate electrospinning technique is established. The design ideas and fabricating techniques are instructive for fabricating poly-functional yarns. The fluorescence-magnetic-conductive yarns are potential candidates in lighting devices, biomedical imaging and electromagnetic shielding.