The invention relates to an oil-gas separation device and a gas turbine engine. The oil-gas separation device comprises a cavity structure provided with a separation cavity. The wall face of the separation cavity is provided with an inlet, a first outlet and a second outlet. The inlet comprises multiple tangential channels. The multiple tangential channels enable oil-gas mixture to enter the separation cavity in the tangential direction. The first outlet is arranged in the radial direction of the separation cavity, the second outlet is arranged in the axial direction of the separation cavity, the separation cavity is rotated to achieve oil-gas separation for the oil-gas mixture, oil obtained after separation flows out through the first outlet, and gas obtained through separation flows out through the second outlet. In the embodiment of the oil-gas separation device and the gas turbine engine, the oil-gas mixture entering the separation cavity has the large tangential speed and small or almost zero radial speed and axial speed, standing time of vortical motion of the oil-gas mixture in the separation cavity can be longer, and the oil-gas separation efficiency can be better improved.