Abstract: The hexagonal barium ferrite(BaFe₁₂O₁₉, BAM) is considered to be the next generation self-biased millimeter wave ferrite with the most potential application. In this study, barium ferrite films with thickness of 200 nm were prepared by pulse laser deposition（PLD）, which have high remanence ratio and low ferromagnetic resonance linewidth. In the process of deposition, the oxygen pressure is the key parameter. The deposited BaM films have high purity phase composition and high c-axis orientation; when the oxygen pressure is 180 mtorr, the surface roughness of the films is better than that of the BaM films when the oxygen pressure is 90 mtorr; the hysteresis loop test shows that the films have an out of plane orientation, with a large magnetic anisotropy, the rectangular ratio is 0.95, and the saturation magnetization is 4πMS is 3900 Oe. When the pressure of oxygen decreases, the coercivity of BaM film increases from 3000 Oe to 5000 Oe, and the rectangularity of the loop decreases slightly. At the same time, the saturation field of easy axis increases from 5000 Oe to 15000 Oe, which indicates that the decrease of oxygen pressure leads to the decrease of magnetic anisotropy of the film; the ferromagnetic resonance linewidth of BaM film deposited at 180 mtorr oxygen pressure is 140 Oe（@10 GHz）.