Reduced graphene oxide (rGO) covered sulfur loaded on carbon fibers have been fabricated by combinations of melt-flow and electrochemical coverage strategies. rGO layers can serve as conductive composite and protective layer to improve the specific capacity and cycling stability of S/carbon fiber based LSB. Display omitted •Carbon fibers and rGO as conductive components supply double transporting paths of electrons.•rGO as blocking layers inhibits the soluble sulfur diffusing into electrolyte.•rGO layers as another redepositing places increase the utilization of sulfur. To improve the electrochemical performance of Li-S batteries, a cathodic material (rGO150/S/CF-75) was fabricated for Li-S batteries by adopting a melt-flow method to load sulfur on biomass-derived carbon fibers, then the reduced graphene oxide was electrochemically covered on the outside surface of the sulfur. The coverage of reduced graphite oxide layers endows the performance of S/CF-75 multiple improvements. The specific capacity of rGO150/S/CF-75 cathode delivers a specific capacity of 1451.4 mAh g−1 at 0.1 A g−1. The specific capacity of rGO150/S/CF-75 cathode can still maintain 537.3 mAh g−1 after 1000 cycles at 5 A g−1 (109 % capacity retention). The excellent performance of rGO150/S/CF-75 cathode is benefit from not only the conductive paths of reduced graphene oxide layers and protective function of reduced graphene oxide layers inhibiting that the soluble sulfur diffuse into bulk electrolyte, but also the redistribution of sulfur on conductive carbon components during the cycling process.