This paper used two-dimensional nonlinear finite element method to analyze the stress-deformation behavior of high earth-rock cofferdam on deep overburden foundation in two typical conditions. It also analyzed the sensitivity of stress and deformation of high earth-rock cofferdam aiming at different layers of deep overburden foundation and different physical and mechanical parameters of cut-off wall. The results showed that in the impoundment period, the larger tension stress appeared at the bottom of the cutoff-wall;the elastic modulus changes did not largely affect the horizontal and vertical displacement of the cutoff-wall, but obviously affect the large and small principal stress of cofferdam body. The internal friction angle between cut-off wall and both sides of soil has little influence on horizontal and vertical displacement but has certain influence on the large and small principal stress.