Adapting to the need for long reach waterway regulation technology systematically, we developed the water and sediment calculation core parallel program of TK-2DC software, and applied the parallel computing technology to the long reach flow and sediment mathematical model, which improved greatly the computation efficiency and timeliness of long reach flow and sediment simulation of model computing. We also established the long reach flow and sediment mathematical model including Shashi to Jianli, Daijiazhou to Guniusha long reach plane 2D water and sediment mathematical model in the middle reach area of the Yangtze River, and Anqing to Nanjing related waterway regulation project in the lower reach of the Yangtze River, and carried out a model forecast of waterway regulation engineering effects.