Wiring systems powered by highly efficient superconductors have long been a dream of scientists, but researchers have faced practical challenges such as finding flexible materials. Here we report superconductivity in Nb2PdxS5-δ fibers with transition temperature up to 7.43 K, which have typical diameters of 0.3-3 μm. Superconductivity occurs in a wide range of Pd (0.6 < x <1) and S (0 < δ <0.61) contents, suggesting that the superconductivity in this system is very robust. Long fibers with suitable size provide a new route to high-power transmission cables and electronic devices.