In this study, nano-sized SnO2 decorated on carbon cloth (SnO2/CC) is prepared through a simple and facile solid method. The nano-sized SnO2 is uniformly distributed on the surface of carbon fibers in carbon cloth, providing sufficient free space to relieve volume expansion and reduce electrode pulverization during cycling. The as-prepared SnO2/CC as a flexible, self-supporting and additive-free anode electrode for sodium-ion/lithium-ion batteries (SIBs/LIBs) can demonstrate outstanding electrochemical performance. SnO2/CC after annealing at 350 °C (SC-350) as an anode for SIBs can deliver a reversible capacity of 0.587 mA h cm−2 at the current density of 0.3 mA cm−2 after 100 cycles. In addition, when cycling at 1.5 mA cm−2, SC-350 can maintain 1.69 mA h cm−2 after 500 cycles when used as LIB anode. These results illustrate that the as-prepared SnO2/CC can be a promising flexible anode material for flexible SIBs/LIBs and provide a simple and practical method for designing new flexible electrode materials.