The present disclosure relates to a method of manufacturing a curved joined glass sheet having excellent optical quality by adjusting a radius of curvature of a curved thick glass sheet and a radius of curvature of a curved thin glass sheet. The method includes preparing a curved thick glass sheet having a first radius of curvature, manufacturing a curved thin glass sheet having a second radius of curvature by heating and molding a flat plate thin glass sheet, providing a joining film or an adhesive agent between a concave surface of the curved thick glass sheet and a convex surface of the curved thin glass sheet, and elastically deforming the curved thin glass sheet to join the elastically deformed curved thin glass sheet so as to match with the concave surface of the curved thick glass sheet.