Abstract: The experiment mainly conducted the effect of three different structure diaphragm plates in the complex passages on heat transfer and pressure drop characteristics of turbine blade trailing edge. A thermochromic liquid crystal method was used to measure the detailed heat transfer coefficients on the end wall surfaces. Comparison of end wall heat transfer and pressure drop characteristics was made among three kinds of diaphragm plates: rectangular diaphragm plates, 90° and 120°waved diaphragm plates in the complex passages of turbine blade trailing edge. It is found that two waved diaphragm plates produces higher heat transfer with relatively less press drop rather than the rectangular diaphragm plates, and the 90° waved diaphragm plates has higher heat transfer than the 120° waved diaphragm plates in the first passage. In the second passage the two conditions almost have the same effect, while the 90° diaphragm plates cost a higher pressure drop.