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Plastic deformation will be produced in the process of manufacture and service for the titanium bearing equipment, which will affect its fatigue resistance. In order to study the effect of pre-strain on the fatigue crack propagation behavior of commercial pure titanium TA2, fatigue crack propagation tests were carried out on the original material and the materials with 10%, 20% and 30% pre-strained value. Combined with the digital image correlation (DIC) technology, the strain fields at the crack tip were obtained, and the effect of pre-strain on the strain field at the crack tip was researched. The results show that, with the increase in pre-strained value, the propagation rate decreased during the steady-state fatigue crack propagation stage, meanwhile the crack opening displacement decreased and the crack opening load increased, and the plastic zone at the crack tip, the plastic deformation and the cyclic plastic strain accumulation decreased. Therefore, the pre-strain inhibits the plastic deformation and cyclic plastic accumulation at the crack tip, which leads to the more obvious crack closure effect, thus inhibiting the crack propagation. The research results have reference significance for the safety evaluation of titanium bearing equipment.