This study investigates the catalytic mechanisms of Prussian blue nanozymes (PBNZ) as peroxidase (POD) and catalase (CAT) mimetics, revealing their unique self-increasing catalytic activity. Unlike previously reported Fe₃O₄ nanozymes, which exhibit depletable POD-like activity, PBNZ maintain and even enhance their catalytic performance over prolonged reactions. The key to this enhanced activity lies in the irreversible oxidation of PBNZ, which promotes catalysis and leads to a dual-path electron transfer mechanism. This mechanism involves both the valence band (VBP) and conduction band (CBP) pathways, enabling efficient electron transfer during catalysis. The study demonstrates that PBNZ can sustain catalytic activity for extended periods due to the formation of Fe(III) and oxygenated groups, which enhance both VBP and CBP. The results highlight the unique advantage of PBNZ, which exhibits self-enhancing POD and CAT-like activities, compared to natural enzymes and iron-based nanozymes. The dual-path electron transfer mechanism thoroughly explains the catalytic behavior of PBNZ, ensuring a long service life. The findings provide insights into the catalytic mechanisms of PBNZ and their potential applications in various fields.This study investigates the catalytic mechanisms of Prussian blue nanozymes (PBNZ) as peroxidase (POD) and catalase (CAT) mimetics, revealing their unique self-increasing catalytic activity. Unlike previously reported Fe₃O₄ nanozymes, which exhibit depletable POD-like activity, PBNZ maintain and even enhance their catalytic performance over prolonged reactions. The key to this enhanced activity lies in the irreversible oxidation of PBNZ, which promotes catalysis and leads to a dual-path electron transfer mechanism. This mechanism involves both the valence band (VBP) and conduction band (CBP) pathways, enabling efficient electron transfer during catalysis. The study demonstrates that PBNZ can sustain catalytic activity for extended periods due to the formation of Fe(III) and oxygenated groups, which enhance both VBP and CBP. The results highlight the unique advantage of PBNZ, which exhibits self-enhancing POD and CAT-like activities, compared to natural enzymes and iron-based nanozymes. The dual-path electron transfer mechanism thoroughly explains the catalytic behavior of PBNZ, ensuring a long service life. The findings provide insights into the catalytic mechanisms of PBNZ and their potential applications in various fields.