Abstract: x wt% Al₂O₃(x=0, 1.0, 1.5)/BaTi_0.85Sn_0.15O₃(BTS) ceramics were prepared by the traditional secondary solid state reaction method. And the effects of BTS ceramics doped with Al₂O₃ on the microstructure, dielectricity and flexoelectricity were studied. The results show that BTS ceramics doped with Al₂O₃ are still the standard perovskite crystal structure, Al₂O₃ reduces the size of the grain effectively. When Al₂O₃ doping amount increases, the dielectric constant of Al₂O₃/BTS ceramics decreases, the dielectric loss of Al₂O₃/BTS ceramics decreases, the Curie peaks broaden and shift to the high temperature direction. With the increase of Al₂O₃ content and test temperature, the flexoelectric coefficient of Al₂O₃/BTS ceramics decreases.And there is a near linear relationship between the coefficient of deflection and dielectric constant of Al₂O₃/BTS ceramics, but when the temperature is very close to the Curie temperature, the linear relationship is weakened.