Abstract: In this paper,super singularity boundary iutegral is transformed into Cauchy principal value integral in boundary stress integral equation,The existance of theprincipal value integral is demenstrated and the explicit formula of its scale extra term in thesubstitution of variables is given out.Then the main submatrix of supersingularity and thematrix of stress singularity parameters are expressed as a linear combination of non-diagonalsubmatrices in the same row by using rigidbody movement method and unit st...