Abstract: In order to study the influence of the geometric structure of the perforated plate in plant xylem ducts on water transmission, the models of different types of perforated plates were established, combined with Bernoulli equation, and the method of computational fluid dynamics was used for the ducts with different geometric structures of perforated plates. The internal flow field was numerically simulated. The relationship between the pressure drop at both ends of the catheter, the hydraulic conductivity and the equivalent length of the perforated plate, and the perforation type, equivalent area ratio, number of holes, inclination angle and the inner diameter of the perforated plate were analyzed. The results showed that, for a specific perforated plate model, when other parameters were the same, compared with a simple perforation plate, the equivalent length of the gnetum type perforation plate increased by 15.01%, and the pressure drop at both ends of the catheter increased by 3.92%. The equivalent length of the reticulate perforation plate increased by 112.76%, and the pressure drop at both ends of the duct increased by 29.43%. The equivalent length of the scalariform perforation plate increased by 148.70%, and the pressure drop at both ends of the duct increased by 38.81%. The equivalent length of the ephedroid perforation plate increased by 205.70%, and the pressure drop at both ends of the catheter increased by 53.68%. For these 5 types of perforated plates, larger equivalent area ratio, more holes, smaller angle of inclination and larger pipe diameter meant that the pipe ends had greater pressure drop and perforated plates had a larger equivalent length. When the number of holes in the perforated plate was constant and other parameters were the same, the hydraulic conductivity of the duct was proportional to the inner diameter of the duct. The hydraulic conductivity of the duct where the perforated plate was located obeys the following order（from big to the small）: non-perforated plate, simple perforated plate, gnetum type perforated plate, reticulate perforated plate, scalariform perforated plate, ephedroid perforated plate. The research results provided a theoretical basis for in-depth study of plant xylem water transport characteristics.