Method for transporting steel box girder to shallow water area or deep and thick mud flat area on water

The invention provides a method for transporting steel box girders to a shallow water area or a deep and thick mud flat area on water, which comprises the following steps: S1, building a sliding rail bracket, extending one end of the sliding rail bracket to a channel, extending the other end of the sliding rail bracket to the shallow water area or the deep and thick mud flat area, and slidably mounting a girder transporting vehicle on the sliding rail bracket; s2, the steel box girders are hoisted to a girder transporting vehicle from the transport ship through a floating crane on the transport ship in the channel, the steel box girders are transported to the position under the installation position of the steel box girders along the sliding rail support through the girder transporting vehicle, and the installation position is located in a shallow water area or a deep and thick mud flat area; and S3, after the steel box girder is lifted to the designed elevation through a deck crane or a cable crane, installa