Abstract: In order to reduce the noise effect of urban water conservancy landscape facilities on people's life, the mechanism of water noise generation mechanism under different upstream flows different downstream water depths and different weir heights was studied by using physical model test. The water noise generated by the water discharge and the water pressure in the weir toe slab were measured. The results showed that the noise and pressure values will increase as upstream flow and weir height increase, and decline with the increase of downstream water depth. Through analysis of the experimental data, it is concluded that the water noise generated from the urban water conservancy landscape is mainly composed of two parts: one caused by the impact of the water discharge on the toe slab of broad-crested weir, and the other caused by the flow turbulence. In the future, the impulsive water noise and the turbulent water noise will be studied separately to find out the active noise reduction measures for the water noise in broad-crested ridge-free weir.