p-type binary copper oxide semiconductor films were prepared by reactive magnetron sputtering method, and the controlled growth of Cu2O, CuO and Cu4O3 thin films was realized by adjusting the oxygen flow rate. The surface morphology of the films was observed by scanning electron microscopy. Meanwhile, the structure of the films was characterized by X-ray diffractometer and Raman spectroscopy. Measured by UV-Vis spectrophotometer, the band gaps of Cu2O, CuO and Cu4O3 thin films are 2.89 eV, 1.55 eV and 2.74 eV, respectively. In order to further study the surface physical properties of Cu2O, CuO and Cu4O3 thin films, Kelvin probe force microscope (KPFM) was used to directly measure the contact potential difference between film and probe tip (VCPD). The results indicate that the surface work functions of Cu2O, CuO and Cu4O3 thin films gradually decrease with the increase of temperature.