Abstract: Tailings flood discharge system is a necessary part of the tailings safety facilities，flood discharge system design is one of the core problems in the tailings design.According to the characteristics of the tailings flood discharge system inlet water depth is limited， the commonly used several types of flood discharge system commonly used are introduced，the basic flow pattern (weir flow，and half pressure flow，pressure flow) are analyzed，and the analysis results show that the water inlet section is the key parameters affecting the weir flow，inlet depth is a key parameter to affect half pressure flow，pipe (hole) cross section is the key to affect the pressure flow parameters.For various flow pattern of flow rate with the increase of the inlet head speed was analyzed，and the results show that flow from the weir flow into half pressure，increase speed will be significantly reduced，half pressure flow increase speed is greater than the pressure flow.Under certain inlet water depth and the maximum discharge，the reasonable discharge curve is given，according to reasonable discharge curve flood discharge system design is optimal，only the weir flow participate in the flood regulating calculation，simplifies the process for flood regulating calculation，and finally expounds the tailings flood discharge system design and optimization of concrete steps.

Key words: Tailings pond, Flood discharge system, Flow regime, Flood regulating calculation, Discharge curve