An optical waveguide-type soft photoactuator based on an optical micro/nanofiber includes an optical micro/nanofiber, a first deformed material membrane, and a second deformed material membrane. One end of the optical micro/nanofiber is provided with a taper region and a waist region, and the taper region and the waist region are encapsulated in the first deformed material membrane. The second deformed material membrane covers a side of the first deformed material membrane, and the first deformed material membrane or the second deformed material membrane is doped with a photothermal conversion material. The refractive index of the first deformed material membrane is less than the refractive index of a core of the optical micro/nanofiber. The coefficient of thermal expansion of the first deformed material membrane and a coefficient of thermal expansion of the second deformed material membrane are different.