Abstract: Deep mines are usually faced with high ground stress mining environment， and high ground stress reacts to the process of rock blasting.In order to study the influence of unidirectional initial load on the blasting crater，the influence mechanism of initial load on blasting cracks was analyzed， and then the lateral blasting model tests and numerical simulation analysis were carried out.The results indicated that the degree of influence of the initial loaddepends on the magnitude of the explosion load and rock mechanical parameters. And the rock fissure zone was mainly controlled by the relationship between tensile stress and tensile strength. Within the range of the rock fissure zone， the closer to the center of the blasthole， the smaller the effect of the applied load on the fissure. When within the elastic deformation stage of the stress-strain curve of the concrete model， the initial load showed a certain inhibitory effect on the blasting effect. Compared with the no-load state， the unit consumption of explosives at 5 MPa and 10 MPa increased by 35.80% and 90.12%. And the K50 and K80 at an initial load of 10 MPa could be reduced by 1.65% and 0.44%， respectively， indicating that the initial load could also reduce the blasting block rate to a certain extent， which was beneficial to improve the blasting block distribution.The numerical simulation results were in good agreement with the model tests，the research results have certain theoretical guiding role in optimizing the blasting parameters for deep mining.

Key words: initial load, blasting block, lateral blasting model test, numerical simulation