Because it is difficult to achieve p-type doping of Ga₂O₃, Ga₂O₃ photodetectors based on p-n heterojunction have received widespread attention. As a natural p-type oxide semiconductor, CuAlO₂ is a very potential candidate material for forming a heterojunction with Ga₂O₃ due to its large hole mobility. In this manuscript, the electronic structure and properties of Ga₂O₃/CuAlO₂ heterojunction have been investigated by computational and experimental methods. The binding energy and electron localization functions are calculated to investigate the stability of heterojunction and the bonding mechanism between layers. The electron transfer effect has been explored by calculating the charge density difference, Bader charge and the plane-averaged electrostatic potential drop across the interface. The results show that the stability and electron transfer effect of Ga₂O₃ with oxygen-copper terminal of CuAlO₂ are stronger than that of oxygen-aluminum terminal of CuAlO₂. The partial states density indicates that the Ga₂O₃/CuAlO₂ heterojunction has the potential advantage of regulating the band structure without doping. Finally, Ga₂O₃/CuAlO₂ heterojunction is prepared and the results of XPS and PL test are in good agreement with the calculated results. Our results demonstrate that Ga₂O₃/CuAlO₂ heterojunction has a great potential as a candidate structure for the Ga₂O₃ UV photodetector.