Abstract: In order to provide optimal blasting parameters for Miaogou Iron Mine transmitted from open-pit to underground mining，combining the practical situation of the mine design，four schemes are designed on blasting parameters of underground sublevel caving，where the length of blasting resistance line is 1.8 m and the hole bottom distance is taken as main parameters.For the four medium and deep hole blasting schemes，numerical simulations along with comprehensive evaluation and analysis of blasting effect are carried out.Numerical simulation shows that all the four kinds of blasting effective stress can break the rock.The hole bottom distance has no significant influence on blasting effective stress.Explosive cost，mining sites and suitable block rate are taken as main factors to evaluate blasting effect.Through fuzzy comprehensive evaluation，it is concluded that the blasting parameter is optimal when the hole bottom distance is 2.52 m，which provides data basis for mine construction.

Key words: Pillarless sublevel caving, Blasting parameters optimization, Numerical simulation, Fuzzy evaluation