In order to analysis the crack lengths of the different rocks which penetrated by the linear shaped charge jet with uneven thickness clad for cutting excavation, the ANSYS/LS-DYNA code was used to simulate the penetrating process which three kinds of rocks had been penetrated. The results show that: through simulating the penetrate process by eight kinds of linear shaped charge jet with uneven thickness clad, the longest crack was found in Gneiss, the shortest crack was found in Iron ore and the crack length of Granite in between. For the linear shaped charge in this record, the good effect was obtained through taking the uneven thickness clad which vary rate was 2%.The linear shaped charge jet with vary rate of less than 2% slightly was suitable for Gneiss, the linear shaped charge jet with vary rate of more than 2% slightly was suitable for Iron ore, and if Granite was penetrated by linear shaped charge jet with uneven thickness clad, the shaped charge which has 2% vary rate would be more appropriate. It is believe that through the features of penetrated rocks mentioned in the paper, new rock material can be applied easily for pre-splitting blasting engineering in cutting excavation.