The invention belongs to the technical field of building structural engineering and relates to a radial spherical plain cable-strut system for a suspended dome structure. The radial spherical plain cable-strut system comprises an upper node of a radial spherical plain bearing stay bar, a stay bar and a lower node of an un-slideable stay bar. The upper node of the radial spherical plain bearing stay bar comprises a node lug plate, a node semi-circular pipe reinforcing rib, a stay bar lug plate, a first radial spherical plain bearing and a first pin shaft; the lower node of the un-slideable stay bar comprises an upper cable clamp, a lower cable clamp, an annular cable clamp, a radial pull rod lug plate, a radial pull rod, a second radial spherical plain bearing and a second pin shaft. According to the invention, the defect of pre-stress loss caused by friction of the traditional cable-strut system in a stretch-draw stage can be eliminated; an annular rope and the lower node of the stay bar are fixed all the time in the stretch-draw stage; the pre-stress is exerted by the annular swinging of the upper node of the stay bar. The cable-strut system provides a full new stretch-draw annular cable mode and is simple in structure and clear in force transmission.