Abstract: A sofa with adjustable coupled headrest and backrest includes a base movably connected with a side panel and a coupling sheet for backrest hinged at the side panel, and a backrest assembly including a connection element of backrest with a front end hinged at a rear end of the side panel at an upper positionn and a connection rod of backrest with an upper end hinged at a rear end of the connection element of backrest, and with a lower end hinged at the coupling sheet for backrest, the base is provided with a drive member to switch a backrest frame to a lying position, and a coupling assembly for headrest configured to force the connection element for headrest to flip relative to a backrest skeleton is provided between the connection rod of backrest and the connection element for headrest.