Abstract: Based on the numerical simulation of tide waves along the north channel of the Yangtze estuary, a 2D tidal current mathematical model is established to study the tidal wave variation in the Yangtze estuary under the conditions of topographic changes. The research results show that after the completion of the Yangtze estuary deepwater channel regulation works, the high and low tidal levels in the north channel increase, and the tidal range decreases; at the same time, there is a remarkable lag of phase of the flood tide and ebb tide, an intensive deformation of the tidal waves, and the maximum flood and ebb currents increase after the north channel terrain remains unchanged. When the water depth of the north channel increases, the high and low tidal levels in the north channel fall down, and the tidal range increases, and there is a slight phase leading of the ebb tidal level. The increase in water depth along the north channel has gradually slowed down the deformation of the tidal waves, and as a result of the regulation works, the maximum flood tide velocities decrease and the maximum ebb velocities increase.