In this paper, a new GaSe/ZnS van der Waals heterostructure (vdWH) is devised and subjected to systematic analysis through first principles calculations in terms of its geometric, electronic and transport properties. The stability of GaSe/ZnS vdWH is verified through binding energy, phonon spectrum, and ab initio molecular dynamics (AIMD) simulation. Additionally, detailed calculations of plane average electron density difference and average electrostatic potential in the features of GaSe/ZnS vdWH interface are provided. The results show that GaSe/ZnS vdWH comprises a heterostructure with a direct band gap of 2.19 eV and high carrier mobility. Among them, the electron mobility along the x direction reaches 1 394.63 cm2·V-1·s-1, while the electron mobility along the y direction reaches 1 913.18 cm2·V-1·s-1, demonstrating excellent performance and potential applications in electronic nano devices.