In this work, different amount of Cr₂O₃ (x=0∼0.3 wt.%) as dopant were doped into the Aurivillius-type Bi_2.8Gd_0.2TiNbO₉ (BGTN) ceramics, such a kind of Gd/Cr co-doped BTN ceramics with improved electrical properties were synthesized by the convenient solid-state reaction route. The substitution of Cr³⁺ for Ti⁴⁺ at B-site induced the lattice distortion of pseduo-perovskite layer. Fewer Cr₂O₃ dopant (x˂0.2) resulted in the grain refinement of ceramics. After Cr₂O₃ was added into BGTN, T_C decreased to the vicinity of 908 °C. Below T_C, the relaxed dielectric response resulted from charge carriers hopping induced another board dielectric permittivity peak, whose starting temperature shifts toward lower temperature gradually with increase of x. The values of E_a^con calculated from the Arrhenius relationship between σ_ac and T indicated the intrinsic conduction at high temperature is dominated by the long-range migration of doubly ionized oxygen vacancies. Moderate Cr₂O₃ dopant (x=0.1∼0.25) are conducive to the enhancement in both piezoelectric property and thermal stability. The sample with x=0.2 achieved both a high T_C∼909 °C and a high d₃₃∼18 pC/N at the same time. Also, its d₃₃ can retain 80% of the initial value after the sample was annealed at 800 °C for 4 hours.