The experimental models of ribbed channel with different angles were designed in order to analyze the flow field characteristics and heat transfer mechanism of the internal ribbed channel of turbine blade. The statistical average characteristics and unsteady flow field of typical section of the channel were analyzed by flow visualization experiment and particle image velocimetry experiment. Reducing angle can reduce the blocking effect of the rib on the fluid and increase the longitudinal range and strength of the vortex behind the rib when the angle between the spoiler and the flow direction is between 60°~90°. The reflux strength of the first rib increases first and then decreases with the decrease of angle, and the longitudinal impact strength of the second rib increases. The oblique rib structure can improve the peak Reynolds stress of the mainstream fluid and the intercostal fluid, enhance the intensity of intercostal disturbance and improve the heat transfer characteristics of the channel. Reducing angle can improve the amplitude and frequency of velocity oscillation, and improve the heat transfer efficiency of the channel. Reducing angle can increase the energy and energy fluctuation frequency of the fluid flow along the rib, and make the vortex easier to exchange energy with the target surface in the process of backward shedding.