(Bi0.5Na0.5)0.935Ba0.065(Zn1/3Nb2/3)xTi(1−x)O3-0.005Er (BNBT-xZN-Er) multifunctional ceramics were prepared by a traditional solid-phase reaction method. The ferroelectric, dielectric, and photoluminescence properties of BNBT-xZN-Er ceramics doped with different (Zn1/3Nb2/3)4+ complex ions were systematically investigated. The results emerge that (Zn1/3Nb2/3)4+ can be completely diffused in the BNBT-xZN-Er ceramics lattice. With the addition of complex ions, the long-range ferroelectric order of BNBT-xZN-Er ceramics was significantly disrupted, and the electric field-induced strain responses was promoted. The maximum bipolar strain of 0.35% was obtained by introducing (Zn1/3Nb2/3)4+ with a concentration of x = 0.0100, corresponding to d33* (Smax/Emax) of 500 pm/V. Two dielectric anomaly peaks emerge at TR−E and Tm due to the transformation of the phase. Additionally, the ceramics have bright up-conversion photoluminescence properties under a 980 nm laser light source, exhibiting intense green emission bands at 526 and 547 nm. The results illustrate that the BNBT-xZn-Er ceramics exhibit excellent ferroelectric properties and also obtain bright up-conversion green photoluminescence properties.