The continuous and uniform Na3V2(PO4)3/C nanofibers are successfully synthesized through room-temperature pre-reduction with oxalic acid assisting electrospinning method for the first time. With the reduction and chelation of oxalic acid in the spinning solution, the V5+ can be reduced to V3+, and the viscosity and conductivity of the solution are well modified, so that the precursor and the final product nanofibers have more uniform, surface-smooth morphologies without spindle-like protrusions. The sample shows the well-crystallized rhombohedral Na3V2(PO4)3 phase and excellent electrochemical performances. The initial discharge specific capacity of the sample at 0.05C reaches up to 114.0 mAh g−1 and still remains 78.1 mAh g−1 at 10C rate. The capacity retention after 100 cycles at 0.05C still holds 97.0%, and the coulombic efficiency is always close to 100%. The causes that the Na3V2(PO4)3/C nanofibers exhibit good rate performances, cyclic ability and structural reversibility can be mostly ascribed to the perfect nanofibers. The uniform and smooth Na3V2(PO4)3/C nanofiber consists of Na3V2(PO4)3/C nanoparticles uniformly embed in the perfect 1D carbon nanowire, which builds up a continuous network with highly efficient electronic and ionic channels, thus the impressive properties can be realized.