The construction of surface bioactive coating is an effective way to improve the osseointegration ability of metal-based implants. In this study, bioactive hydroxyapatite (HA) coating was fabricated on the surface of porous tantalum (Ta) scaffolds by electrochemical deposition method. The construction of HA coating significantly enhanced the hydrophilicity of porous Ta and increased its specific surface area. The in vitro bioactivity evaluation via simulated body fluid immersion confirmed that the surface of HA coated scaffold was covered with bone-like apatite layer after 3 days of soaking. The in vitro cell culture using MC3T3-E1 cells showed that all porous tantalum scaffolds had good cytocompatibility. After culturing for 5 days, the proliferation rate of the bioactive porous Ta scaffold was 1.1 and 1.4 fold significantly higher than that of the unmodified porous Ta and control groups, respectively, suggesting greater potential on promoting cell adhesion and proliferation. The bioactive porous tantalum scaffold could rapidly induce the deposition of bone-like apatite and promote the attachment and proliferation of osteoblasts on its surface, suggesting its great clinical application prospect in the fields of bone repair.