A modular backwash assembly and method for using the same is disclosed, the modular backwash assembly comprises a filter brick body, an ultrasonic generator and an ultrasonic connecting component, the filter brick body is provided at an upper portion with a square trench and a cover, the square trench is provided with a plurality of stiffeners and fillers, and a conductive channel is provided on the periphery of the square trench and is provided with an ultrasonic conductive medium therein. The invention has the advantages of firm structure and durable, the gas distribution uniformity may be increased up to 96% and the turbidity average is below the specification 10 NTU.