The invention provides a method for manufacturing an aluminum
oxide insulator resistant to 300kV direct-
current voltage. The method comprises the following steps: step S1, performing isostatic pressing to form a cylindrical
ceramic green body; s2,
processing the shape of the green material, and turning an umbrella skirt; s3,
sintering the processed
green body material into
ceramic to form a cooked body; s4, the size of the cooked blank is subjected to finish
machining, upper and lower connecting end faces and hole sites are machined, and a
ceramic insulation column is formed; s5, a
metal top plate and a
metal bottom corner are machined; s6, a
metal top plate and a metal bottom corner are assembled at the upper end and the lower end of the ceramic insulation column respectively; and S7, spraying an insulating layer on the surface of the ceramic insulating column. By adopting the ceramic
green body made of high-purity aluminum
oxide, the whole ceramic insulation column is integrally sintered and formed, the bearing effect is better, the insulation performance is better, the total height design size is reduced, the bearing requirement is met, and meanwhile the
machining and assembling cost is saved.