A projection-type display system includes: a projection-type display apparatus that alternately switches images for the left eye and images for the right eye and projects the images onto an object; and an opening and closing control device that receives a control signal based on the display states of the images projected onto the object by the projection-type display apparatus and controls switching apertures of stereoscopic image viewing glasses corresponding to left and right eyes, wherein the projection-type display apparatus is connected to one end of a LAN cable and the opening and closing control device is connected to the other end of the LAN cable.