Abstract: Nano TiN films can be used to inhibit the secondary electron multiplication of high frequency ceramic windows, shorten the high power aging time of devices, and improve microwave emission performance. In this paper, nano-titanium nitride (TiN) films were successfully prepared on the surface of ceramic windows by using the DC magnetron reaction sputtering method of coaxial cylindrical target and planar target by special vacuum coating equipment and optimizing the preparation process parameters. Modern analytical methods such as scanning electron microscope (SEM), X-ray diffractometer (XRD) and X-ray photoelectron spectrometer (XPS) were used for testing and analysis. The results show that the surface of the TiN film has fine grain size and good density. The crystal planes (111) and (200) feature diffraction peaks with regular peak shapes and narrow peak widths. The atomic stoichiometric ratio of Ti/N is close to 1∶1. With the increase of the deposition time of the film, the secondary electrons emission coefficient (SEY) gradually increases, and SEY is 1.72 when the sputtering time is 8.4s. With the increase of matrix bias, the ionization efficiency increases, and SEY decreases continuously. When the bias voltage is 350 V, the SEY is 1.89. With the increase of nitrogen flow, SEY changed, and when the N₂ flow was 38 mL/min, the lowest SEY was 1.83.