Effects of various factors on ultrasonic degradation of acid fuchsine using high-heat treated industrial nano TiO2 were studied. The results indicate that the effectiveness of ultrasonic degradation is more obvious with anatase nano TiO2 than that with rutile nano TiO2. Under conditions of ultrasound frequency of 25 kHz, power out put of 50W, catalyst amount of 500mg/L, pH=3.0 and initial concentration of 10mg/L, the degradation rate of acid fuchsine can get to 80% in 60 min, and be close to 100 percent in 180 min, and elimination rate of COD is close to 99%. Therefore, ultrasonic degradation of organic pollutants by TiO2 catalyst has better prospects.