According to measured hydrological and suspended sediment data from spring tides in Bohe Bay, the suspended sediment transport flux was divided into several dynamic items using the mechanism decomposition method, and the mechanism of suspended sediment transport was analyzed in terms of the advection sediment transport, tidal pumping effect, and vertical circulation transport. The results show that the Lagrangian residual current basically moves in the direction of the flood tide and its value increases with the distance from the shore. The Euler residual current has a value similar to the Lagrangian residual current, while the value of the Stokes residual current is close to zero. The advection is the leading factor affecting the suspended sediment transport and the transport effect of the Euler residual current is correlated with preferential flow in the tidal process. The tidal pumping effect in Bohe Bay does not have a strong influence on the suspended sediment transport, and it is induced by the asymmetry of the tidal current and suspended sediment concentration. The vertical residual circulation has a weak effect on the suspended sediment transport and is related to the vertical distributions of the Lagrange residual current and suspended sediment concentration.