In the paper, the 3-D multi-mathematical model COHERENS was adopted to simulate the transport and diffusion of concentrated brine into coastal waters. The concentrated brine discharged model was applied to Laizhou Bay. Three experiments on different combinations of temperature and salinity were designed. Based on the different diffusion situation of concentrated brine, it is found that the higher temperature is propitious to the spreading of the brine under the same conditions, and the increased salinity is not conducive to the spread of brine. In the actual project, these features can be taken advantage of. By adjusting the discharge parameters of the concentrated water, the engineer can minimize the adverse effects of the concentrated water.