Adding biological filler and sludge into the reactor, adding simulated wastewater, and then aerating. Don't aerate too much in the early stage, and keep bubbles as small as possible to provide a relatively stable environment for microorganisms. 12h later, stop aeration, and discharge the upper suspended sludge and wastewater. Then change the water every 12h until the biofilm matures. The time can be changed, not necessarily 12h. Domestication, if the treated sewage contains refractory organic matter, it is necessary to add a small amount of refractory organic matter at the beginning and gradually increase the concentration to the set value.