Perovskite heterostructure has a honeycomb lattice when a bilayer along the 111 direction is considered. The material usually presents a wealth of unique properties. Recently, (111)-oriented perovskite heterojunctions have received more and more attention. In this work, the first-principle calculations are employed to investigate the electronic and magnetic properties of (SrVO₃)₅/(SrTiO₃)₁ (111) heterostructure. The calculations show that the ground state of (SrVO₃)₅/(SrTiO₃)₁ (111) heterostructure is a half-metallic ferromagnet. Further study reveals the existence of different correlated-electron ground states in (SrVO₃)₅/(SrTiO₃)₁ (111) heterostructure, and they can be tuned by changing in-plane strain and interfacial cation intermixing. This system can keep half-metallic properties under difffferent in-plane strains from –4% to 2%. The half-metallic properties mainly come from V 3d electrons. The ground state of the system can evolve from a half-metal to a antiferromagnetic insulator if the in-plane compressive (tensile) strain is added up to 8% (4%). The interfacial Ti-V intermixing can destroy the original half-metallic properties, and the system exhibits a ferromagnetic insulator phase. These results demonstrate that the system has potential applications in the field of spintronics, and provide a theoretical reference for the use of (SrVO₃)₅/(SrTiO₃)₁ (111) heterostructures to explore quantum phase transitions.