NOVELTY - Preparing fusing carbonate fuel battery nickel oxide (NiO) cathode material by water base casting, comprises: (a) mixing carbonyl nickel powder, pore-forming agent, dispersing agent, wetting agent and distilled water; milling the mixture to obtain first slurry; adding bonding agent and plasticizer, and milling to obtain the second slurry; putting into vacuum to be homogenized; (b) casting the slurry; drying to obtain electrode blank; cutting the blank into needed size according to actual needs; controlling the thickness of the electrode blank; and (c) sintering the casted electrode blank.    USE - The process is useful for preparing fusing carbonate fuel battery nickel oxide cathode material by water base casting (claimed).    ADVANTAGE - In utilizing the process, the prepared porous NiO electrode has smooth surface, uniform quality and has no cracks. Moreover, the process takes water base solvent to replace organic solvent; thus, it reduces production cost and environmental pollution.    DETAILED DESCRIPTION - Preparing fusing carbonate fuel battery nickel oxide (NiO) cathode material by water base casting, comprises: (a) mixing carbonyl nickel powder, pore-forming agent, dispersing agent, wetting agent and distilled water; milling the mixture to obtain first slurry; adding bonding agent and plasticizer into the first slurry, and milling to obtain the second slurry; putting the second slurry into vacuum to be homogenized and to eliminate the air bubbles; (b) casting the slurry prepared by casting method on the surface of polyethylene thin film; drying to obtain electrode blank with uniform quality, higher flexibility and strength; cutting the blank into needed size according to actual needs; controlling the thickness of the electrode blank through adjusting the height and speed of scraping cutter of the casting machine; and (c) sintering the casted electrode blank to obtain porous NiO electrode which has smooth surface, uniform quality and has no cracks; where the sintering process comprises heating the material at room temperature to 850 degrees C; where the temperature increasing speed from room temperature to 240 degrees C and from 350 degrees C to 500 degrees C is 2 degrees C/minute; the remaining is 1 degrees C; and the temperatures of 240 degrees C, 350 degrees C, 500 degrees C, and 850 degrees C are maintained for 120 minutes, 240 minutes, 120 minutes, and 30 minutes; and sintering at 850 degrees C and naturally cooling at room temperature to prepare the fusing carbonate fuel battery NiO cathode material.