Abstract: An experimental comparison research of endwall heat transfer characteristics was conducted in the complex passages of turbine blade trailing edge by using thermochromic liquid crystal method. Three kinds of diaphragm plates between two passages were studied to obtain optimal heat transfer effect. Results indicate that the radial inflow cooling air in first passage passes through the orifices in the diaphragm plates ceaselessly then changes to spanwise cooling air, which impinges the second passage and flows away through the orifices along the trailing edge can enhance heat transfer of the trailing edge; uniform configuration of orifices in diaphragm plate provides better heat transfer effect than that of others.