Stilling pool base slab belongs to a light structure, the characteristic of this structure including vibration, impact, stability and so on, are directly related to the flow fluctuation intensity of the hydraulic jump region on the base slab. Based on a certain project, we make systematic research on fluctuating pressure characteristics of underflow pattern stilling pool base slab and guide wall, by the way of synthetic analysis of flow fluctuation pressure testing data, the distribution of hydrodynamic pressure on stilling pool base slab was generally drawn out, as well as the conversion relationship of point and area fluctuation pressure. This paper enriches and develops the research on fluctuating pressure characteristics of underflow pattern stilling pool base slab and guide wall, moreover, provide scientific reference for further research on flow dynamic characteristics of this kind of energy dissipation pattern.