N/Ti3+　co-doping　multiphasic　TiO2/BiOBr　heterojunctions　(NT-TBx)　were　prepared　by　one-step　in　situ　hydrothermal　processes.　The　crystal　phase,　morphology,　component,　and　optical　properties　of　the　heterojunctions　were　characterized　by　X-ray　diffraction,　scanning　electron　microscope,　transmission　electron　microscope,　X-ray　photoelectron　spectroscopy,　and　Ultraviolet-visible　diffuse　reflectance　spectroscopy　techniques,　respectively.　The　as-prepared　samples　exhibit　better　sonocatalytic　activity　for　the　degradation　methylene　blue,　Rhodamine　B,　and　p-Nitrophenol　aqueous　solution　compared　with　pristine　TiO2　and　N/Ti3+　co-doping　multiphasic　TiO　2　.　Especially,　the　highest　degradation　ratio　of　methylene　blue　was　achieved　for　NT-TB0.3　up　to　98.2%　after　50　min　under　ultrasonic　irradiation.　The　high　sonocatalytic　activity　has　been　kept　after　four　cycles　with　the　tiny　decline,　indicating　the　excellent　stability　of　the　as-prepared　samples.　The　improvement　of　sonocatalytic　activity　could　be　attributed　to　the　formation　of　doping　level　and　multiphasic　TiO2/BiOBr　heterojunctions,　which　account　for　the　absorption　of　long　wavelength　light　and　the　electron-hole　pair　separation,　respectively.　Furthermore,　superoxide　radical　(O-center　dot(2)-)　was　demonstrated　to　be　the　main　reactive　species　for　the　degradation　of　methylene　blue　under　ultrasonic　irradiation.　This　study　provides　a　facile　fabrication　procedure　for　N/Ti3+　co-doping　multiphasic　TiO2/BiOBr　heterojunctions　and　demonstrates　an　efficient　route　to　promote　the　application　of　TiO2　in　addressing　environment-related　issues.