How to treat and reuse the excessive sludge effectively and economically has become the most important task in wastewater treatment investigation. It is the significant precondition and key to the follow-up treatment. A new-style cavitator was developed which had ventilation and rotating function to disintegrate excessive sludge cells. These designs could avoid blocking and save energy. The cavitator was used to disintegrate the excessive sludge cells, and the disintegration effect was evaluated by the dissolution rate of the intracellular matters. The operating parameters were optimized through the orthogonal experiments. While the cavitation number was1.8 and the ventilation ratio was 1.4%, the unit energy consumption was 600W/kg. If 1 m3 of excessive sludge was treated for 30 minutes, 1000 MJ of energy would be consumed, which was lower than that of ultrasonic method by 40%. In the first 10 minutes, the average dissolution rate of SCOD was 0.06%/s.