In design of water conservancy project, reservoir scour funnel shape, size before dam and the corresponding flow characteristics of water are directly related to the normal operation of discharge structure. According to the study of local scour funnel before dam which was determined by the model test of Aertashi reservoir, the variety rule of vertical and horizontal funnel configuration under different operation conditions were concluded. The paper provided the discharge flow and flushing duration that maintain the power hole being clear front. Compared with test results of similar projects, the test result is reasonable and practicable and can provide reference for design.