The surface of sodium-calcium tempered glass was treated by low temperature plasma generated by atmospheric pressure bipolar nanosecond pulse dielectric barrier discharge (DBD). The DC flashover voltage under different treatment time was measured, and the physicochemical properties of the material surface before and after treatment were measured by water contact angle measuring instrument, atomic force microscope and Fourier transform infrared spectrometer. The results show that plasma treatment accelerates the reaction between gas in air and the material surface, introduces hydrophilic groups on the material surface, enhances surface hydrophilicity, and thus reduces the flashover voltage of the material. On the other hand, the etching effect of plasma increases the surface roughness of the material. Under the action of the electric field, the local field strength is severely distorted, and the flashover channel is more likely to form, so the flashover voltage is reduced.