The invention belongs to the technical field of space device protection and in particular relates to a space device external armor based on a flexible structure. The space device external armor basedon the flexible structure comprises multiple flexible pressure bearing units; each flexible pressure bearing unit comprises a module base, a pressure bearing surface and multiple flexible pressure bearing arms connected between the module base and the pressure bearing surface; the multiple flexible pressure bearing arms are distributed in the circumferential direction; and the module base is connected with a space device. The space device external armor based on the flexible structure is used for spacecrafts (such as a space station and a satellite) in the outer space for a long time, outsideimpact is reduced, and the spacecraft is prevented from being collided and damaged by small aerolites or other space trashes.