The experiment results of the prior dam partition stuffing of permeability are analyzed and arranged. By the two dimension seepage calculation and analysis of the 1+180 representative section, the combination of disadvantaged computation parameters are ascertained. According to it, the seepage control effect of the static pressure grouting is analyzed and calculated at the condition of core wall without cracks. And the seepage state of which core wall leads to cause the horizontal crack and the seepage control effect of the static pressure grouting are analyzed. The calculation showed that the injecting cement paste can make up the partial size shortage of the core wall of the old dam effectively. When some extreme conditions of the core wall occurs such as cracks to arise simultaneously, the static pressured grouting body can control the leakage effectively. Also the status of the greater seepage gradient of the dam shell gravel at backward position is indicated. So the filter layer is set behind the drainage filter and in front of the ward wall reasonably to improve the stability of the dam shell materials at backward position.