AbstractThe cross‐compatibility of electronic devices and biomedicine has greatly promoted the new medical diagnosis and treatment technology. Developing biodegradable resistive random access memory device (ReRAM) with low power is key to biomedical application. In this paper, the all‐inorganic air‐stable and high‐quality AgBi2I7 perovskite‐like film is successfully prepared by introducing Ag+ into the Bi‐I system. The device has a higher ON/OFF ratio after annealing in NH3 compared with annealing in vacuum, and the switching behavior changes from gradual type to abrupt filamentary type. Meanwhile, ultralow power characteristic with the set power of 6.9 × 10–7 W (0.42V@1.6 × 10–6A) and the reset power of 1.5 × 10–8 W (1V@1.5 × 10–8A) is achieved in the Ag/AgBi2I7/ITO memory devices after annealing in NH3. Good biodegradability is affirmed via put Ag/AgBi2I7/ITO device in PBS solution. Results show that the Ag/AgBi2I7/ITO memory devices are the promising candidate in the field of biomedical application.