Abstract: To address the issues of discontinuous material feeding and low mechanical properties of deposited layers in the traditional friction stir additive manufacturing process of 2219 aluminum alloy, continuous wire feeding friction stir additive manufacturing was proposed, and a study on the effect of the T6 heat treatment process on mechanical properties was carried out. Test results show that the internal microstructure of the 2219 aluminum alloy additive-manufactured components fabricated by continuous wire feeding friction stir additive manufacturing is dense; the action area of the central stirring pin exhibits a uniform layered stacking morphology, and the interlayer bonding is sound. The design of the eccentric stirring pin with symmetrically distributed dual-channel female threads enhances the plastic flow effect of interfacial materials and ensures metallurgical bonding at the intra-layer and inter-layer interfaces of deposited layers. Microhardness tests are conducted on the as-deposited components, and the results indicate that the microhardness values of the components are uniform. After T6 heat treatment, the hardness improves significantly, reaching 156.4 HV. The tensile strength of the as-deposited components in the travel direction is 244 MPa ± 5 MPa, and the elongation after fracture is 17.5% ± 0.5%. After T6 heat treatment, the tensile strength and elongation after fracture reach 411 MPa ± 17 MPa and 9.4% ± 2.2%, respectively, and the fracture morphologies all exhibit typical ductile fracture characteristics.