With the acceleration of the urbanization process, many urban sewage treatment plants have been established in China, and the output of sludge has also increased rapidly. How to further improve the efficiency of sludge treatment, especially the efficiency of resource treatment, is a hot topic of current research. Sulfate radical has oxidation, and persulfate oxidation technology using sulfate radical is a new oxidation technology in the field of sludge treatment. It can be used for pretreatment of sludge, greatly reducing the moisture content of sludge, cracking the stable structure of sludge, so as to improve the utilization rate of sludge resources. In this study, sodium persulfate pretreatment sludge was activated by three activation methods: thermal activation, alkali activation and ultrasonic activation to achieve the effect of cracking the stability of sludge. In this paper, the effect of activated sodium persulfate pretreatment of sludge was studied under the conditions of 80 ℃ water bath heating, pH of 13 alkaline and ultrasonic frequency of 2000 Hz. The experimental results were indicated by the changes of chemical oxygen demand, sludge particle size, three-dimensional fluorescence and protein. The experimental results show that the three methods can promote the cracking of sludge, among which the ultrasonic activation at 2000 Hz frequency for 75 min and the water bath heating at 80 ℃ for 20 min can effectively promote the cracking of sludge, and are the most economical and efficient activation treatment methods in the pretreatment sludge.