The length of the pre-splitting crack is an important parameter in underground mine deep-hole blasting, and experience and engineering analogy methods are used commonly, but they seldom have scientific and theoretical basis. In this paper, the mature numerical analysis software - ANSYS/LS-DYNA was adopted, the different lengths of pre-splitting crack were simulated. In the filling body, the corresponding maximum blasting vibration velocity and stress are obtained by numerical simulation when the maximum initiation section blasted. The corresponding regression formulas are obtained by using the...