Coaxial In2O3/Bi2MoO6 heterostructured nanobelts have been synthesized by combining a facile single-spinneret electrospinning with post-heat treatment. In2O3 layers (150 ± 10 nm in thickness) are uniformly coated on the continuous Bi2MoO6 cores (600 ± 20 nm in diameter). A possible formation mechanism of coaxial heterostructured nanobelts is proposed according to the theory analysis and experimental study. The as-fabricated coaxial In2O3/Bi2MoO6 nanobelts exhibit the enhanced electrochemically assisted photocatalytic activity and excellent reusability for 4-NP degradation under simulated sunlight irradiation. Therefore, it is reasonable to believe that the coaxial In2O3/Bi2MoO6 heterostructured nanobelts may have the promising applications in many photoelectronic devices.