Coupling　photocatalysts　with　photonic　crystals　structure　is　based　on　the　unique　property　of　photonic　crystals　in　confining,　controlling,　and　manipulating　the　incident　photons.　This　combination　enhances　the　light　absorption　in　photocatalysts　and　thus　greatly　improves　their　photocatalytic　performance.　In　this　study,　Ga2O3　photonic　crystals　with　well-arranged　skeleton　structures　were　prepared　via　a　dip-coating　infiltration　method.　The　positions　of　the　electronic　band　absorption　for　Ga2O3　photonic　crystals　could　be　made　to　locate　on　the　red　edge,　on　the　blue　edge,　and　away　from　the　edge　of　their　photonic　band　gaps　by　changing　the　pore　sizes　of　the　samples,,　respectively.　Particularly,　the　electronic　band　absorption　of　the　Ga2O3　photonic　crystal　with　a　pore　size　of　135　nm　was　enhanced　more　than　other　samples　by　making　it　locate　on　the　red　edge　of　its　photonic　band　gap,　which　was　confirmed　by　the　higher　instantaneous　photocurrent　and　photocatalytic　activity　for　the　degradation　of　various　organic　pollutants　under　ultraviolet　light　irradiation.　Furthermore,　the　degradation　mechanism　over　Ga2O3　photonic　crystals　was　discussed.　The　design　of　Ga2O3　photonic　crystals　presents　a　prospective　application　of　photonic　crystals　in　photocatalysis　to　address　light　harvesting　and　quantum　efficiency　problems　through　manipulating　photons　or　constructing　photonic　crystal　structure　as　groundwork.