[Abstract]: In the existing railway reconstruction project of Kunshan Lujiabang section of Beijing-Shanghai railway, the through steel truss beam with the span of 80m across the channel of Qingyang port is constructed by incremental launching method. The key contents of bridge construction and the main system of incremental launching are introduced, and studies the improvement of the incremental launching device system.The steel truss assembly support is combined with the bridge substructure to form the incremental launching construction platform. According to the working principle of the long-distance jack, the integrated self-anchored jacking device is combined with the slideway to form the self-anchored power system. The incremental launching device integrates the jack and the reaction frame into a whole, and the jack and the reaction frame move forward synchronously. The incremental launching system has the advantages of convenient installation, high jacking efficiency and greatly reducing the number of operators.