The uplift pressure acting on a bottom of debris flow check dam can counteract partial effective weight and reduce the overturning stability of the dam. To study the distribution laws and influence factors of uplift pressure

a check dam model and an acquisition system of uplift pressure were designed and produced. A series of simulation tests of uplift pressure was conducted based on different gully bed slopes and different accumulations in front of the dam heel. The experimental results show that the uplift pressure linearly decreases from dam heel to dam toe. When placing accumulations in front of the dam

the absolute values of correlation coefficients between the uplift pressure and the distance to dam heel exceed 0.98. The uplift pressure decreases with the increase of gully bed slope and the influence of the bed slop on the pressure at the dam heel is greater than that of the dam toe. The permeabilities of materials placed on gully bed and accumulations in front of the dam all have impacts on uplift pressure. The lower their permeabilities are

the lower the uplift pressure will be. The permeability of accumulation in front of the dam heel also has a marked impact on the distribution laws of uplift pressure; and the lower the permeability is

the more obvious the distribution laws are. These research results will be the basis of further study on process and mechanism of uplift pressure acting on a bottom of check dam.