Abstract: Secondary electron emission yield(δ) is one of the key parameters affecting the Hall thruster sheath. In this study, we employed two technologies, laser etching and surface coating, to suppress δ of BN-SiO₂. The construction of microarray structures on the surface of the sample is achieved by using a pulsed infrared fiber laser. The characterization of the surface structure is achieved by the laser scanning microscopy. The measurement of δ relies on the collecting method. The results show that the optimum δ suppression is achieved by the process parameters of 10 W laser power and 50 scanning cycles. The δ peak values of two BN-SiO₂ samples are reduced from 2.62 and 2.38 to 1.55 and 1.46, respectively. Subsequently, a TiN thin film was deposited on the laser etched microstructures by utilizing the magnetron sputtering to realize a better δ suppression. The characterization results show that a plenty of nanoscale trigonal structures distribute on the surface of the fabricated TiN film, and the film thickness is about 246 nm. For the BN-SiO₂ microstructures, after coating the TiN film, the δ peak values of two samples are reduced from 1.55 and 1.46 to 0.82 and 0.76, which achieves a significant δ suppression compared to the original surface. In this study, the δ of BN-SiO₂ ceramic is significantly reduced by surface etching and TiN film deposition. The study is of significance for engineering applications to achieve low δ surfaces in some necessary occasions.