The embodiments of the present disclosure provide a 3D display device and a manufacturing method thereof. The 3D display device includes a first substrate; a second substrate disposed opposite to the first substrate; a black matrix; and a grating. The black matrix and the grating are disposed on a side of the first substrate facing away from the second substrate; the black matrix and the grating are disposed in a same layer; and a side of the first substrate where the black matrix and the grating are located is a light exit side of the 3D display device.