Abstract: The work instruction system includes: a computer configured to generate a work instruction screen; and a display device connected to the computer and configured to display the work instruction screen. The work instruction screen includes a first display region in which a three-dimensional model used for describing an assembly work of an object is displayed based on three-dimensional design data, a second display region 320 in which at least a part of attribute information of the three-dimensional design data is displayed, and a third display region in which when predetermined component information registered in advance is included in the attribute information, related information associated with the predetermined component information is displayed. In the first display region, when the object is a wiring line, the three-dimensional model is displayed for allowing a first predetermined operation.