A simple and efficient sonochemical method was developed for the degradation of organic matter and ammonia nitrogen in azodicarbonamide wastewater. The effects of initial pH, ultrasound format and peripheral water level on the sonolysis of hydrazine, urea, COD and ammonia nitrogen were investigated. It is found that the initial pH has a significant influence on the degradation of hydrazine and ammonia nitrogen, whereas this impact to urea is relatively small. It also shows that a noticeable enhancement of ammonia nitrogen removal could be achieved in a proper intermittent ultrasound operation mode, i.e., 1/1 min on/off mode. The height difference between the peripheral water level and the inner water level of the flask affects the efficiency of ultrasonic treatment as well.