Abstract: Based on the tie rod fracture problem occurring during the perforation and combined fracturing operation of a soluble ball seat, this paper analyzes the fracture causes of the tie rod through macroscopic fracture analysis, force analysis, chemical composition analysis, hardness testing, metallographic structure analysis and tensile property tests. The results show that the main factors leading to tie rod fracture are insufficient tensile strength and poor microstructure and properties of the material. Meanwhile, three improvement measures for preventing tie rod fracture are proposed, including increasing quenching and tempering hardness, optimizing the heat treatment process and improving the structural design of the tie rod.