Abstract: J-integral tearing modulus inter-section method（J-T） for limit load and critical crack length calculation in LBB technology is introduced.J-integral of cracks with three kinds of crack length are calculated by finite element program ABAQUS firstly,then the relationship between J-integral and crack length is surrogated by a polynomial,and the limit load and critical crack length are obtained based on the polynomial at last.The validity of the J-T method is checked by an example provided by FLET program.The results demonstrated that precision of unstable J-integral calculation is improved by the ABAQUS-based J-T method,and the proposed method is more universal and suitable for the LBB analysis of complex structures.