Abstract: For seeking the cause of the leakage in turbine condenser, eddy current testing was applied in the titanium tube around the leakage tube. Combining the two typical eddy impedance signals and using the standard detection program, we can deduce the demarcating curve which can be used to calculate the thickness loss of titanium tube. The leakage of titanium tube lies in the tube defects and the stress on account of power unit startup and stop. Abrasion between the titanium tube and the separating plate causes the defects of titanium tube. The fixing vertical angle of separating plate and concentricity of the row affect the assemble clearance between the titanium tube and separating plate.