In the primary loop of nuclear reactor, corrosion products will deposit on the fuel surface and increase the thermal resistance between coolant and fuel, resulting in insufficient safety margin, which may lead to reactor shutdown in serious cases. In this study, a prediction model of the deposition rate of corrosion products on the fuel surface of the plate fuel element is established by using CFD method. Considering the influence of coolant scour on the deposition rate, a thermal resistance model of the deposit layer is established to study the deposition behavior of corrosion products on the surface of the plate fuel and the influence of the deposit layer on the fluid-structure coupled heat transfer of the fuel assembly. The results show that the deposition rate is affected by fuel power and coolant flow rate, and the thickness of the deposited layer increases with the decrease of coolant flow rate and the increase of power density. The change of coolant flow rate will change the time when the deposit reaches stability, and greatly affect the size of the deposition thermal resistance. At low speed, the deposition thickness reaches 20.14 μm, and the additional thermal resistance, about 1.372 × 10–5 m2·K/W, is introduced, resulting in a temperature increase of 17.7 K. The simulation method and conclusion adopted in this study can provide important reference and technical reserve for the calculation of corrosion deposition of plate fuel elements.