A vehicle headlight device 100 according to the present invention includes a first lamp 92 that has a light source 211, an optical system 21, a rolling mechanism 50, and a control circuit 60. The optical system 21 includes a first wedge prism 30 and a second wedge prism 40 in which an incident ray from the light source 211 is deflected and projected. The rolling mechanism 50 rotates the first wedge prism 30 about a rotation axis. The control circuit 60 controls the rolling mechanism 50 so that the first wedge prism 30 is rotated in a direction opposite to a vehicle bank direction in accordance with a vehicle bank angle d. The first wedge prism 30 and the second wedge prism 40 are disposed so that their surfaces perpendicular to the rotation axis face each other. The first wedge prism 30 is disposed so that a wedge angle a1 directs in a road surface direction. The first wedge prism 30 is disposed so as to be rotatable about the rotation axis.