Rock mass slope saturated and unsaturated seepage issue under flood discharge atomized rain is a major problem which will be faced in the high dams of the southwest area of China. Firstly

the movement character of slope water and factor influencing the seepage under the flood discharge atomization is analyzed theoretically. Secondly

according to the control equation of saturated-unsaturated states

the integral saturated-unsaturated unsteady seepage control equation is constituted in connection with saturation degree. Thirdly

the three-dimensional FEM program for computing saturated-unsaturated unsteady seepage under ground permeation condition is developed; the unsaturated hydraulic parameter problem and initial water head field problem in the FEM is treated. Finally

based on the proposed method

the seepage field under flood discharge atomization of slope in Goupitan Hydroelectric Station at right bank is simulated. The result can provide an important reference for slope rock mass seepage control. The result shows that the flood discharge atomized rain seepage can lead to temporary saturated area in the slope surface and groundwater table hoist; the temporary saturated area size and groundwater table amplitude depend on the protection of slope surface

drainage and purdah etc. So

the slope surface protection should be strengthened

and the measures of drainage

purdah of slope should be set up rationally in order to reduce seepage and groundwater table hoist.