Green technologies for the removal of organic pollutants from aqueous environments have become essential, with sonocatalysis emerging as a promising method. However, the development of effective sonocatalysts is crucial for the successful degradation of organic pollutants. This research presented the composite-hydroxide-mediated process for BaCO3/BaNbO3 composites and used for sonocatalytsis. The results showed that the optimum molar ratio of 1:5 BaCO3/BaNbO3 composite was found to have the highest sonocatalytic degradation efficiency of Acid Orange 7 (AO7), which reached 96.62 %. After four cycles, the degradation rate of AO7 remained high at 89.24 %, demonstrating the sonocatalyst strong stability and reusability. Furthermore, free radical trapping experiments confirmed that free radicals and holes are the primary agents responsible for AO7 degradation during sonocatalysis. The enhanced sonocatalytic activity of the 1:5 BaCO3/BaNbO3 composites could be attributed to the BaCO3 addition, which reduced the interfacial resistance and effectively enhanced the charge-hole separation. Finally, the mineralization rate of AO7 was found to be as high as 80.13 % in the total organic carbon (TOC) test, indicating that AO7 was ultimately degraded into harmless CO2 and H2O. Therefore, this study offers valuable insights into the application of niobates in acoustic catalysis and their potential role in the remediation of aquatic environments.