Architecture of fibrous building blocks with ordered structure and high electroactivity that enables quick charge kinetic transport/intercalation is necessary for high-energy-density electrochemical supercapacitors. Herein, we report a heterostructured molybdenum disulfide@vertically aligned graphene fiber (MoS2@VA-GF), wherein well-defined MoS2 nanosheets are decorated on vertical graphene fibers by C–O–Mo covalent bonds. Benefiting from uniform microfluidic self-assembly and confined reactions, it is realized that the unique characteristics of a vertical-aligned skeleton, large faradic activity, in situ interfacial connectivity and high-exposed surface/porosity remarkably create efficiently directional ionic pathways, interfacial electron mobility and pseudocapacitive accessibility for accelerating charge transport and intercalation/de-intercalation. Resultant MoS2@VA-GF exhibits large gravimetric capacitance (564 F g-1) and reversible redox transitions in 1 M H2SO4 electrolyte. Furthermore, the MoS2@VA-GF-based solid-state supercapacitors deliver high energy density (45.57 Wh kg-1), good cycling stability (20,000 cycles) and deformable/temperature-tolerant capability. Beyond that, supercapacitors can realize actual applications of powering multicolored optical fiber lamps, wearable watch, electric fans and sunflower toys.