Abstract: The limit analysis method is widely used in geotechnical engineering, which can be used to judge the local and overall failure of the rock and soil mass, so the determination of limit strain value is a key.Based on laboratory tests, FLAC3D finite difference method and PFC2D discrete element method, Brazilian splitting tests were carried out on seven types of thick layered limestone samples with different dip angles to study their anisotropic characteristics of tensile mechanical parameters and failure processes, and the results of three methods for determining ultimate tensile strains were compared and analyzed.The results show that the tensile strength and peak strain of layered limestone with different dip angles have anisotropic characteristics.The failure mode of rock samples with dip angles from 0° to 90° gradually changes from matrix tensile fracture to tensile-shear composite failure and bedding tensile fracture.The ordinate of the end point in the elastic stage of the stress-strain curve is determined as the ultimate tensile strain, which is about 70% of the tensile strain at failure, and when the strain exceeds the ultimate tensile strain, cracks begin to initiate and expand and entering a plastic stage.The ultimate tensile strain values obtained by the three methods have similar variation laws with the change of dip angle, and the magnitude difference is small.The combination of laboratory test and numerical simulation can show the whole process of crack initiation, extension and penetration of bedded limestone samples from a macroscopic level, which has important guiding significance for the parameter value selection in engineering design.