Tantalum (Ta) has considerable potential for clinical application in artificial vertebral bodies owing to its excellent biocompatibility. A novel Ta artificial vertebral body structure was engineered by combining thin-walled structure topology optimization with lattice structure filling design methods. Three types of Ta artificial vertebral bodies were prepared using selective laser melting. The influence of sidewall curvature on the mechanical properties and deformation behavior of artificial vertebral bodies was investigated through compression tests and finite element analysis. The elastic modulus and yield strength of the Ta lattice structures were observed to range from 1.75 to 3.21 GPa and 31 to 65 MPa, respectively. The incorporation of topologically thin walls resulted in enhancements of the elastic modulus and yield strength by factors of 2.26 to 3.77 and 3 to 3.62, respectively. A decrease in sidewall curvature was associated with an increase in the elastic modulus and yield strength of the artificial vertebral body. Specifically, when the sidewall curvature decreased from 0.027 to 0 mm^-1, the elastic modulus and yield strength of the artificial vertebral body were enhanced by factors of 2.76 and 2.19, respectively. The yield strengths of the artificial vertebral bodies were comparable to that of human cortical bone. AVB-2 exhibited the highest yield-strength-to-elastic-modulus ratio (0.029) in comparison to AVB-1 and AVB-3 (0.024 and 0.019, respectively). This finding suggests that the optimal sidewall curvature of the artificial vertebral body is 0.014 mm^-1. AVB-2 effectively mitigated the stress shielding effect while maximizing the load-bearing function, indicating its significant potential for clinical applications.