Method for transforming steel ladder into concrete ladder in towering concrete structure

The invention discloses a method for transforming a steel ladder into a concrete stair in a towering concrete structure. The method comprises the following steps that firstly, step plates, platform plates and handrails on the steel ladder are dismantled, and steel ladder beams are reserved; a formwork is erected by taking the steel ladder beams as positioning foundations, concrete of cantilever concrete ladder beams is poured to form the cantilever concrete ladder beams taking the steel ladder beams as inner supports, and meanwhile, concrete of the concrete platform plates is poured between the cantilever concrete ladder beams on the two sides; and after the concrete reaches the designed strength, a prefabricated concrete stair is erected between the concrete platform plates, and the handrails are mounted. Original steel ladder beams do not need to be dismantled, the concrete stairs are arranged on the basis of the original steel ladder beams, and the problem that the steel ladder beams are difficult to disma