Lithium−sulfur (Li−S) batteries are of great interest in next-generation flexible electronic devices for their much higher energy density. However, current Li−S batteries are still facing the problem about rational construction of the flexible power sources. Herein, a novel flexible and integrated electrode is fabricated through a non-solvent induced phase separation (NIPS) method with poly(m-phenylene isophthalamide) (PMIA) as the flexible support for Li-S batteries. Notably, the integrated electrode shows the capability of adapting the volume expansion of cathode materials, inhibiting the diffusion of lithium polysulfides and suppressing the dendrite growth of Li. As a result, battery assembled with the fabricated electrode exhibits a capacity of 773.6 mAh g−1 at 1 C. After 600 cycles, the capacity still remains at 565.5 mAh g−1 with the calculated capacity fade of 0.045% per cycle. This proposed strategy is advanced and feasible, which has great potential in next-generation portable electronic devices.