Samples are taken from Quankou and Xianning City by drilling which is a representive red clay of Wu Guang special passenger railway. After the analysis dynamic triaxial test on these samples, it get different concretion ratio of unsaturation red clay from 2 labor spots, relation curve of different surround pressure condition lower move shear stress destroy, dynamic stresses, scissors intensity index, dynamic elastic modulus and relevance experiment constant item, which have the reference effect to the design for unsaturation red clay section of Wu Guang special passenger railway.