The In2Se3-doped 2 Se 3-doped Sb phase change material was deposited onto a polyimide substrate using magnetron sputtering technique. A comprehensive investigation was conducted on the thermal stability, bending resistance, crystal structure, and electrical properties of this material. The findings revealed its remarkable thermal stability, data retention, and bending resilience, particularly in the In 0.05 Se 0.19 Sb 0.76 film, which exhibited minimal resistance drift. The aging test confirmed the stability of the electronic structure in In2Se3-doped 2 Se 3-doped Sb, accompanied by reduced structural relaxation. Notably, no new crystalline phase emerged in In 0.05 Se 0.19 Sb 0.76 film, but stronger In-Sb bonds were formed. Raman spectroscopy and bending tests further indicated that deformation had minimal impact on the film's structure and surface. Utilizing the In 0.05 Se 0.19 Sb 0.76 material and polyimide substrate, a flexible phase change memory device demonstrated reliable SET/RESET operations even after bending, offering three stable resistance states for multilevel storage. This enhanced the storage density, making In2Se3-doped 2 Se 3-doped Sb material a promising flexible phase change material with excellent performance and vast potential for applications in phase change storage, such as electronic fabrics and flexible smart wearable electronics.