Abstract: Bayan Obo Iron Mine has now entered into deep mining. The mining technical conditions and engineering geological conditions of the deposit have changed a lot. Especially for large diameter medium-deep hole blasting，the original blasting parameters can not meet the requirements of current open-pit production. How to adjust and optimize blasting parameters and improve blasting quality is of great significance for reducing costs and increasing efficiency in mines. In order to adapt to the variable mining conditions，LS-DYNA finite element simulation software was used to simulate the blasting effects at different intervals between adjacent holes during the formation process of blasting funnel in the magnetite mining area and dolomite area of Bayan obo Iron Mine. Furthermore，the pressure range，stress and strain parameters of shock wave at different time and different position were discussed. Research showed that the hole distance of magnetite mining area ranges from 8 m to 9 m，but not longer than 9 m，and the hole distance of dolomite area is longer than 9 m. Combined with the simulation parameters of mediumdeep hole blasting，the blasting tests were carried out in the ore area，rock area and ore-rock mixed explosive areas of Bayan obo Iron Mine. After optimization，the block rate of blasting was decreased by 0.5 item/104 t，the full-bucket coefficient of excavator was increased by 4 percent points，the discharge time was enhanced by 3.5 s/ set，and the number of damaged shovels or bucket tips is lowered by 1 item.

Key words: Medium-deep hole blasting, Blasting crater, Blasting parameter, Numerical simulation