Multifunctional ceramics of 0.825K0.5Na0.5NbO3-0.175Sr(Yb0.5Nb0.5)O3- x%Er with ferroelectric, transparent and luminescent properties were obtained by doping Er. The effects of Er-doping on the structure, luminescence and electrical properties of the ceramics were studied. After Er doping, the ceramics have luminescent properties and the luminescence intensity reaches the maximum when x=0.75. The ceramics still have good light transmission, but the transmittance decreases with the increase of Er-doping content due to the change of phase structure from pseudo-cubic phase to three-phase orthogonality. The energy storage properties is also greatly improved, and the Wrec and the η of the ceramics reach the maximum value of 0.31 J/cm3 and 94.6% when x=0.25, respectively. At the same time, the maximum electro-induced strain value is 0.031%.