Synchronous construction method for sparse-cable-stayed bridge cable beam

The invention discloses a synchronous construction method for a sparse-cable-stayed bridge cable beam, and relates to the field of cable-stayed bridge construction. A sparse-cable-stayed bridge to be constructed comprises a main tower, a main beam body and a plurality of stayed cables. The method comprises the following steps: firstly, constructing cabled segments, moving hanging baskets forward after construction of the cabled segments, and tensioning a part of steel strands in the stayed cables of the cabled segments; secondly, constructing cableless segments, tensioning the remaining part of the steel strands in the stayed cables of the cabled segments after completing construction of the cableless segments, and then moving the hanging baskets; thirdly, circulating the construction steps till completing construction of the main beam body. The method can save the construction period, and the steel strands cannot be damaged easily.