An orthogonal experiment was made to study the influence of the geometry parameters of straight-through labyrinth seals on sealing characteristics.The geometry parameters studied include the fin tip thickness

seal clearance

fin height

fin pitch

fin front inclined angle and rear inclined angle.The experiment was made with 25 models that were designed according to the orthogonal test method.The results show that various parameters have different influences on discharge coefficient.The best combination of various geometry parameters for sealing in the test range is that fin tip thickness takes 0.1mm

seal clearance takes 0.3mm

fin height takes 3 mm

fin pitch takes 9 mm

fin front inclined angle takes 0 degree and rear inclined angle takes 15 degree .The rank of importance of each parameter's variation from its maximum to minimum value on sealing characteristics is fin pitch

seal clearance

rear inclined angle

fin tip thickness

fin height

fin front inclined angle.Fin pitch is the most important parameter

seal dearance is less important than fin pitch

rear inclined angle and fin tip thickness have certain impact on the sealing characteristics

while fin height and fin front inclined angle have little influence on it.