A　novel　rugby-like　β-Ga2O3photocatalyst　with　a　3D　hierarchically　assembled　porous　structure　was　successfully　constructed　through　a　facile　precipitation-calcination　method.　The　synthesized　Ga2O3materials　were　used　for　the　photocatalytic　degradation　of　tetracycline　hydrochloride　(TC·HCl)　and　the　effects　of　calcination　temperature　on　photocatalytic　activity　were　discussed.　The　conversion　of　TC·HCl　over　Ga2O3-900　was　99.0%　after　25　min　of　UV-light　irradiation,　which　was　higher　than　those　of　commercial　Ga2O3(71.2%)　and　P25　(82.9%).　The　best　photocatalytic　activity　of　Ga2O3-900　could　be　attributed　to　its　large　specific　surface　area,　intrinsic　electronic　properties　and　stable　3D　hierarchically　assembled　porous　structure.　Based　on　the　liquid　chromatography　quadrupole　time-of-flight　mass　spectrometry　(LC-QTOF-MS)　analysis,　the　photocatalytic　mechanism　of　Ga2O3and　feasible　degradation　pathway　of　TC·HCl　were　proposed.　We　believe　that　the　present　study　can　exploit　an　effective　avenue　to　design　photocatalysts　with　3D　hierarchical　porous　structures　to　meet　ever-increasing　environmental　remediation　requirements.　©　The　Royal　Society　of　Chemistry　2020.