Abstract: In order to solve the gas overrun in the upper corner of fully mechanized caving face during primary mining, a long-hole blasting roof caving method was proposed in the open-off cut to fill the goaf for the effective reduction of ventilation section of working face, so as to improve the ventilation condition and gas emission. Due to the limitation of open-off cut's bolting structures, the blasthole spacing was generally greater than the pre-splitting blasting spacing determined by the experienced formulas, and this would result in poor consequences in the pre-splitting blasting. In order to select a suitable method to increase the balsthole spacing in the field, several charge methods were simulated with ANSYS/LS-DYNA, including the decoupling charge, V-shaped notch and split-tube charge methods. The results show that, directional fracture blasting with split-tube charge has obvious advantages in increasing blasthole spacing and protection of rock wall, and the optimal width of split-tube can be determined by numerical simulation. Finally, through the application of the long-hole blasting roof caving in the working face K8205 of Guo Yang company, the comparison of coal pillar stress before and after the blasting as well as one-knife cut shows that the method has good effect on the blasting.