Abstract: It brings many difficulties to the construction because of the large size(7 m×9 m)of the outlet of deep hole for flood sluicing,high hydraulic pressure(80 m) and high level of the outlet tensile stress, many steel bars must being installed and installed on many lays.By means of the finite element analysis, the deep hole structure plan, steel liner in the pressure section plan and the transverse joint grouting plan are deeply researched in order to decrease the outlet tensile stress and reduces the lays of the steel bars. It is clear that the tensile stress decreased when the outlet are under the lateral hydraulic press of the transverse joint. There are 3 layers of steel bars Φ36@20 in the outlet in front of the well of emergency gate, 4 layers of steel bars Φ40@20 in the top of the outlet behind the well and 3 layers of steel bars Φ40@20 in the bottom of the outlet. These steel bars can be dispersed in 2 concrete lifts. The steel liner in the pressure section can limit the slits. The transverse joint grouting can decrease the outlet tensile stress, and the effect has a relationship to the stiffness of outlet wainscot and the width of transverse joint.