Abstract: A mine adopts a bottomless sublevel caving method and a medium-deep hole blasting ways, the ore joints are developed, and the physical and mechanical properties of the ore are complex.It is difficult to determine the strength of the similar test model material for ore blasting.Therefore, according to the similarity theory, this paper analyzes the similarity of ore and sets up the model of three groups of different proportion specimens for mechanical testing.The σ-ε curve of three groups of specimens is obtained by data processing of the test results of the model specimens.The destruction forms of the three groups of specimens are analyzed, the physical and mechanical parameters of three groups specimens are calculated, and the theoretical values of physical and mechanical properties of ore are analyzed with similarity theory.Finally, the strength of the model that satisfies the similar test of ore blasting is obtained.