Embodiments of the present disclosure provide a method for preparing silicon carbide membrane supports using activated coke fly ash. Using activated coke fly ash as a pore-forming agent, micro-sized silicon carbide powder as the primary aggregate, nano-zirconia, alumina, and/or magnesia as sintering aids, and polyvinyl alcohol aqueous solution as a binder. The components are uniformly mixed to obtain a premixed material. The premixed material is extruded via mechanical extrusion to form support green bodies, which are then dried at a constant temperature in a drying oven. Finally, the dried green bodies undergo programmed sintering in a muffle furnace to produce the silicon carbide membrane supports.