In this study, three types of nitinol (NiTi) lattice structures [namely, body-centered cubic structure with Z-axis reinforcement pillars (BCCZ), face-centered cubic structure with Z-axis reinforcement pillars (FCCZ), and face-body-centered cubic structure of shaft reinforced pillars (FBCCZ)] having high stiffness were prepared by applying selective laser melting. The effects of the structure type and the porosity defect on the fatigue property were investigated. The experimental results show that the FBCCZ exhibits the best fatigue performance, reaching 10⁷ loading cycles at the maximum compressive stress of 25 MPa. The BCCZ and FCCZ exhibit poor fatigue performance, reaching 10⁷ loading cycles at the maximum compressive stress of approximately 15 MPa. The analysis results show that when the cyclic loading stress is large, the structure type has a significant effect on the fatigue property of NiTi alloys. The smaller the bending deformation and local stress concentration of the structure, the better is the fatigue property. Therefore, the best fatigue property is exhibited by the FBCCZ, followed by the FCCZ, and the BCCZ exhibits the worst. When the cyclic loading stress is small, the influence of micro defects on the fatigue property becomes significant than that of the structure type. The difference between the fatigue properties of the FCCZ and BCCZ gradually decreases as the cyclic loading stress decreases. The porosity defects in the sample promote the initiation of fatigue cracks and degrade the fatigue performance during cyclic loading.