A method for fabricating an aeration stone is disclosed, which abandoned activated sludge, red soil and an alkaline metal oxide are separately dried firstly and then cracked, and next the cracked abandoned activated sludge, red soil and alkaline metal oxide are separately sieved to obtain smaller grains thereof, and then the grains are separately ground into fine particles thereof and are mixed to be a mixture. Next, the mixture is molded into a green aeration stone. Next, the green aeration stone is fired at a high temperature and then cooled down to obtain a finished aeration stone. Therefore, the present invention recycles the abandoned sludge of wastewater treatment works to reduce the secondary pollution of abandoned sludge.