Abstract: Through the concrete practice and try (experiment) of contol resample mould in the explosion box and testing ground, this paper carries oat an advance blast mechanism of multi-free surface and the calculated formula and charge fix up methed for blast design of unsymmetry hillside with multi-free surfaces. It has been became a new model blasting methed, through trial of the thousands blasting engineering in the twenty years. It can be applied in the blast design of various topography.