Abstract: Oujiang Estuary is located at the confluence of the East China Sea and the Oujiang River, and it is the core area of the coastal industrial belt and an important industrial cluster in Wenzhou City, Zhejiang Province. Based on the investigation and analysis on the hydrology, sedimentology, topography, and sedimentary environment, we studied the dynamic geomorphology evolution and water-sediment transport characteristics of the estuary. Results show that the dynamic geomorphological system of shoal-channel is an important part of the geomorphological pattern of Oujiang River estuary, and the geomorphological pattern is the result of the combined action of Oujiang River runoff and the dynamic conditions of waves, tides, and currents in the estuary. The seabed topography is characterized by the distribution pattern of “channel erosion” in the northern branch and “shoal deposition” in the southern branch. The water transport in the estuary is dominated by the ebb flow in the southern branch, while the flood flow in the northern branch is evident during the spring tide and the ebb flow is evident during the neap tide. At the same time, the asymmetry of tidal currents under the combined action of runoff and tidal currents is obvious. The net sediment transport at the southern mouth of Oujiang River was between 224 and 8876 kg, while at the northern mouth, it was between 20 and 15506 kg, indicating active sediment movement. The dynamic geomorphology and water-sediment environment of the estuary are the result of the relative effects of river and tidal currents, human construction projects in the estuary, and the nearshore circulation system.