Photocatalytic reactive oxygen species (ROS) evolution with Bi5O7I still suffers from sluggish charge carrier dynamics and limited light absorption. Herein, abundant oxygen vacancies (OVs) were introduced into the microflower-like Bi5O7I, and its ROS generation toward organic dye degradation under the synergistic effect of visible light and ultrasound irradiation was investigated. Benefiting from the broadened visible-light absorption range, stronger piezoresponse, and higher carrier transport efficiency in OV-enriched Bi5O7I (2-PEG-Bi5O7I), both its photocatalytic and piezocatalytic degradations were improved. More importantly, its piezo-photocatalytic degradation performance was greater than the sum of the corresponding photocatalysis and piezocatalysis, indicating a strong coupling effect. In addition, the piezo-photocatalytic yield of •O2- with 2-PEG-Bi5O7I was 1.5 times higher than that with Bi5O7I, and it was also 4.3 and 3.1 times higher than its single photocatalysis and piezocatalysis, respectively. Interestingly, no noticeable •OH was detected in the case of visible-light irradiation, while the piezocatalytic and piezo-photocatalytic yields of •OH were 3.6 and 5.3 μmol g-1 h-1, respectively, with OV-enriched Bi5O7I, surpassing the pristine Bi5O7I as well. This work advances the coupling effect between photocatalysis and piezocatalysis as a new strategy for efficient ROS generation and also discloses the positive role of oxygen vacancies in improving multiresponsive catalysis.