The (K0.5Na0.5)(0.95)Li0.05Nb0.95Bi0.05O3-1mol% Er2O3 transparent ceramics were prepared by a pressureless sintering method. The fabricated transparent ceramics not only exhibit high optical transmittance (85.3%) due to dense microstructure (nanoscale size grains), but also show the photochromism-induced light scattering and reversible upconversion (UC)-switching properties by visible light irradiation. Upon 407 nm light irradiation, the optical transmittance intensity is significantly decreased, showing a strong light scattering (Delta Abs = 28.3%). The light scatting degree can be quantitatively reflected by Er3+ ion UC emission, and could be recovered to its initial optical transmittance based on photochromic reactions. Meanwhile, the transparent ceramic is found to maintain good energy storage properties with higher W (5.87 J/cm(3)) and W-rec (1.96 J/cm(3)) under a higher electric field of 260 kV/cm. These results suggest that Er3+ doped (K0.5Na0.5)NbO3 transparent ceramics are promising for the modulation of light scattering and the design of photoelectric multifunction devices.