Large-span oval daylighting roof steel structure support-free installation construction method

The invention discloses a large-span oval daylighting roof steel structure support-free installation construction method. The method comprises the steps that S1, an upturning beam is arranged; s2, building a daylighting roof soft platform; s3, pre-assembling the steel structure main beam; s4, hoisting a main beam shaped like a Chinese character'feng 'of the daylighting roof; s5, steel beam hoisting in the long-axis direction; s6, hoisting an inner ring ring beam; s7, outer ring supporting beam hoisting; s8, hoisting an outer ring ring beam; s9, building of an all-round scaffold is replaced, the problems that the all-round scaffold is high in building height, large in size, long in building and dismantling construction period, large in personnel and material input amount and the like are solved, meanwhile, the lower space of the daylighting roof can be fully utilized, and the large-span oval daylighting roof steel structure roof is convenient to construct; the construction difficulty and the safety risk are re