Flexible support structure suitable for mountainous large-gradient terrain and construction method of flexible support structure

The flexible support structure comprises end beam supports and side anchor piles, the end beam supports are provided with supporting columns, the upper portions and the lower portions of the supporting columns are connected with end beams and the supporting piles respectively, the end beams are provided with connecting plates, the connecting plates of the end beam supports on the two sides are jointly connected with a bearing cable, and the bearing cable is connected with the side anchor piles. Photovoltaic modules are mounted on the adjacent load-bearing cables; stay cables are connected to the connecting plates in the same extension direction of the bearing cables, and the ends, away from the bearing cables, of the stay cables are connected to the side anchor piles. The supporting columns of the end beam support are vertically installed on the angular bisectors of the load-bearing cables and the stay cables, so that the tension on the load-bearing cables and the stay cables can be self-balanced to the maxim