The invention relates to a method for conditioning urban sewage plant excess sludge through ultrasound and Fenton cooperation. The method includes the following steps that S1, the pH value of excess sludge is adjusted to be 2.0-4.0; S2, a Fenton reagent is added into the excess sludge, wherein the Fenton reagents comprises ferrous sulfate with the saturation humidity ratio being 0.5-1.50 g/kgDS and hydrogen peroxide with the saturation humidity ratio being 15-30 g/kgDS; S3, the flow state of the excess sludge is kept through stirring, and an ultrasonic probe is immersed below the liquid level of the excess sludge; S4, ultrasonic frequency is adjusted to be 20-40 kHz, sound energy density is adjusted to be 0.07-0.10 W/mL, ultrasound time is set to be 20-240 s, and the ultrasonic probe is started for reaction; S5, after the ultrasound time is up, the ultrasonic probe is taken out from the excess sludge, the remaining sludge continues to react, and reaction time is 0.25-2 h; S6, after the reaction time is up, conditioning of the excess sludge is finished. The method reduces consumption of the Fenton reagent and ultrasonic conditioning consumption. Meanwhile, dewaterability of the excess sludge is further improved.