Field observations were carried out in the northwestern Caofeidian sea area, a silt‐dominate coast, in Bohai Bay, China. The characteristics of tidal currents, waves, and SSC changes under different hydrological conditions were analyzed. Results show that the SSC is mainly influenced by wave‐induced sediment suspension: under light wind conditions the SSC was very low, with the peak value generally less than 0.1 kg/m 3 $ 0.1\,\,{\text{kg/m}}^{ 3} $ https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429437434/bbbf395f-630d-479f-8f72-2e19316efa69/content/inline-math2_1.tif"/> ; the SSC increased continuously under the gales over 6‐7 in Beaufort scale, with sustained wind action. The measured peak SSC at 0.4m above the seabed was 0.15‐0.32 kg/m 3 $ {\text{kg/m}}^{ 3} $ https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429437434/bbbf395f-630d-479f-8f72-2e19316efa69/content/inline-math2_2.tif"/> , with the average value of 0.08‐0.18 kg/m 3 $ {\text{kg/m}}^{ 3} $ https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429437434/bbbf395f-630d-479f-8f72-2e19316efa69/content/inline-math2_3.tif"/> , which is about 3‐6 times the value under light wind conditions. Field data in other silt‐dominated coasts was collected, such as Huanghua port sea area, Jingtang port sea area and Jiangsu coast. Results show that silt‐dominated sediments are sensitive to flow dynamics: the SSCs increase rapidly under strong flow dynamics (i.e.,  strong tidal currents or waves), and higher concentration exists near the bottom; as a result, the high SSC causes heavy sudden siltation in navigation channels.