Abstract: In a case study of an iron mine,the scheme of underground crushing system is studied,the type selection of crushing equipment is calculated,and the advantages and disadvantages of jaw crusher and rotary crusher are compared.The results show that when underground crushing system scheme is being chosen,if 1 jaw crusher meets the requirements,the jaw crusher should be preferred,and if 1 jaw crusher can not meet the requirements,the selection should be compared and determined according to the specific conditions of the mine.The comparison of the underground crushing system schemes in a 9 million t/a capacity iron mine shows that under this production scale,the crushing scheme with 2 jaw crushers is better than that with one rotary crusher.