Abstract: The turn-over channel of turbine blade is an important part of the internal cooling structure of the turbine blade. Its flow performance is important for the design of cooling structure of the turbine blade.A real turn-over channel of turbine blade is simplified as an object to be studied in the present paper which studies flow performance in a 180° turn-over channel with 90° parallel different height ribs.The efficient pressure distribution in the inner part of the turn-over channel along the channel,including 90° parallel different height ribs,is shown in the paper.The result shows that the efficient pressure distribution in the inner part of these two turn-over channels with 90° parallel rib along the process is similar.Some efficient pressure increases along the channel because of the irregular changing of the channel shape.Correlation formulas of the coefficient of the efficient pressure are obtained in the paper.Resistance coefficient increases with the increase of the rib height to diameter ratio.