Abstract：In order to improve efficiency of the hydro-turbine used in hydraulic fume exhausters, numerical simulations of flow in a whole hydro-turbine were carried out, and the simulated results were compared with the experimental data. The orthogonal experiment method was used to optimize the primary geometric parameters of the turbine. By applying L9(33)orthogonal table, three parameters such as nozzle exit area, nozzle diameter and nozzle length were selected to be experimental factors. The orthogonal optimization design was performed in terms of turbine efficiency, and the range analysis method was used to analyze the experimental results. The orthogonal experiments result show that the nozzle length has the most significant effect on the turbine efficiency, followed by the nozzle diameter and the nozzle exit area. The optimized nozzle length is 389.7 mm, the nozzle diameter is 30 mm, and the nozzle exit area is 92.57 mm2. Compared with the reference hydro-turbine before optimization, the nozzle length is reduced by 10% after optimization, the efficiency is increased by 7.67%, the velocity distribution inside the turbine is even more uniform. Consequently, operating cost of the hydraulic fume exhauster will be reduced. The feasibility of orthogonal experiment method in the hydro-turbine optimization is verified.