Based on a study for the layout of navigation-power junction at Chejiang dam site of Tugutang on Xiangjiang River, we established the orthogonal curve two-dimensional current mathematical model. Firstly the model was verified with the nature current materials, and some parameters were adjusted so that the calculated result by the model was consistent with the real-measured data. Then the emulating navigation-power junction was embedded into this model. By the navigation-power junction simulation model, the typical discharge ways of the junction was simulated, the current distribution characteristics was analyzed, and some parameters relating to navigation including the longitudinal and cross flow in the entrance area of the approach channel and in the approach channel. Finally, the navigation current conditions were evaluated according to the Code for Master Design of Shiplocks (JTJ 305—2001). I revealed the features of less investment and time, abundant fruit and easy scheme optimization of this simulation technique.