A display control device controls display of a virtual image which is superimposed on foreground of a vehicle by projection of a display light image from an optical unit to a projection area. The display control device sets a projection position of the display light image which is projected in the projection area on the basis of a relative position of a superimposition object on which the virtual image is superimposed, obtains a measurement information from one vehicle height sensor measuring a displacement in a vertical direction occurring in the vehicle, obtains a gradient information indicating a gradient of a road on which the vehicle travels on the basis of three-dimensional map data, and corrects the projection position of the display light image on the basis of the measurement information and the gradient information.