A projection control device includes a projection controller configured to control a projector of a head-up display device to project a display image such that a virtual image thereof is viewed in front of a viewer, a video data acquisition unit configured to acquire a captured video captured by an imager capable of capturing a video of the viewer, and a detection unit configured to detect a relative positional relationship of a pupil position of the viewer with respect to the virtual image, wherein the projection control unit is further configured to control the projector to project a reference position determination image on the viewer, and the detection unit is further configured to detect the relative positional relationship of the pupil position of the viewer with respect to the virtual image based on the captured video obtained by capturing the reference position determination video projected on the viewer.