Abstract: In the present paper， the flow field of the liquid under the boat\|type board of rice direct seeder was simulated and analyzed via the module FLOTRAN CFX in the finite element analysis software ANSYS， and the flow line of the liquid at different section thickness was compared considering the viscosity of water and mud sliding resistance. The computation results showed that the depth of the boat\|type board exhibited varied effects to the flow field and liquid flux. Compared with the traditional test methods， the present research method would fully and directly reflect the overall flow status under the boat， and consequently save costs and improve efficiency. Under the given conditions， it was shown that a 60 mm depth of the boat\|type board had the best effects on flow field and flux.

Key words: direct sowing machine, hydrodynamics, boat\, type board thickness, flow rate of the fluid, simulation analysis