Simultaneously employing light and vibration energy by piezoelectric material to realize environmental remediation is an advanced oxidation method. Silver niobate (AgNbO₃) is a visible light driven photocatalyst for the removal of organic pollutants. However, the high recombination rate of photo-generated electrons and holes suppresses its photocatalytic activity. Piezoelectric potential excited by vibration can facilitate the separation of light induced charges. Unfortunately, AgNbO₃ is an antiferroelectric. In this work, distinct photo-/vibration-bi-catalysis has been achieved in ferroelectric (1−x)AgNbO₃–xLiTaO₃ solid solution. The results show that ~96% Rhodamine B (RhB) can be decomposed under the bi-excitation of ultrasound and visible light within 120 min with 0.95AgNbO₃–0.05LiTaO₃ catalyst. The synergy effect from efficient visible light excitation and enhanced separation of the photo-induced charges from the electric field by the mechanical strain results in the distinct decomposition performance of catalysts.