Abstract: The biochemical reacting area is opened up and the bionic fillers are laid directly in the stream in order to purify the stream polluted water body entering a lake and reduce the investment and energy consumption.But this will influence certainly water power condition and its existing function.In this paper, the effect of the bionic fillers on the stream power condition is analyzed by the tests.The results indicate that the turbulent effect of the 9 stems/m² bionic fillers on water flow is low and the water flow gives priority to the laminar flow because of the low velocity in the tested stream.At the same time, the in creasing rate of the roughness coefficient is low, too (the roughness coefficient of the reach with bionic fillers is only 1.08 times as much as the comparison reach), which does not influence on the drainage of the stream.