Landscape dams play an important role in urban river flood control and drainage, as well as urban water landscape construction. However, continuous flow noise is often generated when the dam discharges, which causes pollution to the acoustic environment in the nearshore area of the river. Weir structure, as an integral part of the dam, inevitably affects the discharge noise and propagation characteristics; to clarify its influence, different weir types were studied by field monitoring and numerical simulation. The results show that the difference of flow velocity, turbulence degree and vorticity caused by differences in weir typess has a great impact on the sound source characteristics of discharge noise. Large overflow surface slope and weir height, as well as small thickness of weir body often lead to discharge noise with large sound pressure level; however, the pressure level can be effectively reduced by the stilling basin structure behind the weir. The dissipation noise energy of overflow surface structure with flip bucket has a fast attenuation speed along the course, and has little influence on the acoustic environment. In comparison, the low-frequency energy of the discharge noise of the weir with large slope and small bottom width is relatively strong, which has a greater impact on human health. The research results can provide a technical support for the noise reduction of urban landscape dams.