Abstract: The influence of shape and directionality of hole on leakage characteristics of hole-pattern damping seal was investigated. The CFD numerical solution model for the flow field characteristics was developed to analyze the leakage characteristics of the hole-pattern damping seal, honeycomb seal, labyrinth seal and smooth surface seal under different rotating speed and sealing gap. The influences of hole shape, superellipse coefficient and inclined angle of generalized hole-pattern damping seal on leakage characteristics were discussed to reveal the mechanism of damping seals with directional holes. The results showed that closely arranged hole-pattern damping seal had remarkable superior leakage characteristics compared to labyrinth seal and smooth surface seal. The ellipse-like hole damping seal with an inclined angle of 30°, a superellipse coefficient of 2 and an edge number of 2 has the minimum leakage rate with the absence of rotating speed, the leakage rate of which can be reduced further by reducing circumferential or axial arrangement spacing. The low-speed choke region formed adjacent to the exit of ellipse-like hole with relative large values of superellipse coefficient under a certain inclined angle, contributed to controlling leakage rate and obtained better leakage characteristics.