Highly flexible, binder-free, MoO3 nanobelt/graphene film electrode is prepared by a two-step microwave hydrothermal method. Graphene is first prepared by an ultra-fast microwave hydrothermal method and then mixed with MoO3 solution to synthesize the MoO3 nanobelt/graphene composite, which exhibits the combination of stacked graphene sheets and uniform MoO3 nanobelts with widths of 200–500 nm and lengths of 5–10 μm. The charge–discharge measurements show that the as-synthesized MoO3/graphene hybrid materials demonstrate excellent rate capability, large capacity, and good cycling stability compared to the pure MoO3 film. An initial discharge capacity of 291mAhg−1 can be obtained at 100 mA g−1, with a capacity of 172mAhg−1 retained after 100 cycles. The results show that the MoO3/graphene designed in this study can be used as a free-standing cathode material in rechargeable bendable Lithium batteries.