The removal of emerging contaminants (ECs) from water has been a hotspot and a challenge in the field of environmental engineering. Advanced oxidation processes (AOPs) based on peracetic acid (PAA) activation can generate active species with strong oxidative capability to attack ECs in water. Currently, reported strategies for PAA activation include direct activation, homogeneous activation, and heterogeneous activation. This paper provides a systematic review of the reaction mechanisms of various PAA activation strategies, the degradation performance of typical ECs, and the types and sources of active species in different PAA activation strategies. The main influencing factors of different PAA activation strategies have been analyzed, and a comparison has been made regarding the advantages and applicability of different activation strategies. Finally, considering the challenges faced in the development and application of PAA activation AOPs, future research directions are proposed.