In order to study the influence of slotted spacing on air-gap gathering energy effect of the circumferential slit tube, five types of energy-accumulating blasting models with different slit spacing were established using the ANSYS/LS-DYNA, and the simulation results are verified by steel plate experiment. The results show that the slit spacing is one of the main parameters affecting the formation and effect of air gap shaped charge jet in circumferential slit tube. If the circumferential slit spacing is small,the dense initial cracks will be induced. Which will consume the energy of the gas jet on the rock. If the circumferential slit spacing is large, the wider of slits at the circumferential slits will increase, resulting in non-concentration of energy. When the circumferential slit spacing is 4 cm, Both the numerical simulation results and the steel plate test results show that the average notch depth of this condition is the largest, the blasting effect is satisfactory.