As　a　＂marine　ecological　engineer＂,　the　oyster　reefs　not　only　perform　important　ecological　functions,　but　also　reduce　the　damage　caused　by　waves　to　protective　structures　such　as　seawalls.　However,　oyster　reefs　in　shallow　water　change　the　nonlinear　characteristics　of　waves　and　affect　sediment　transport　and　coastal　evolution.　Based　on　Fourier　spectrum　and　analysis　of　Wavelet　Transform,　the　influence　of　artificial　bag　oyster　reefs　on　the　energy　and　nonlinear　phase　coupling　of　irregular　waves　are　studied　through　physical　experiment.　The　results　show　that　oyster　reefs　have　a　substantial　effect　on　the　energy　of　primary　harmonic,　which　transfer　to　higher　harmonics　through　triad　interactions,　and　a　considerable　reduction　in　primary　harmonic　energy　and　an　increase　in　higher　harmonics　energy　are　reflected　in　the　energy　spectra.　The　transmission　spectrum　behind　the　oyster　reefs　shows　three　peaks　at　primary,　secondary　and　third　harmonics.　The　bicoherence　spectrum　indicates　that　the　peaks　at　secondary　and　third　harmonics　mainly　result　from　the　self-coupling　of　the　primary　harmonics　and　phase　coupling　between　the　primary　and　secondary　harmonics　respectively.　As　the　water　depth　increases,　the　degree　of　nonlinear　coupling　between　wave　components　decreases,　which　leads　to　the　energy　of　wave　components　at　different　frequencies　increases.　With　increasing　top　width,　the　length　of　the　shoaling　region　increases,　and　the　growth　of　triad　nonlinear　interactions　are　observed　in　wavelet-based　bicoherence　spectra,　resulting　in　the　spectral　peak　energy　decreasing　while　the　secondary　harmonics　energy　increasing　in　the　spectrum.　Finally,　the　potential　application　of　an　ecological　system　composed　by　＂oyster　reefs　+　mangroves＂　is　discussed.　As　the　effect　of　water　depth　on　wave　energy　is　much　greater　than　that　of　top　width,　in　artificial　oyster　reef　construction,　it　is　recommended　that　keep　the　oyster　reefs　non-submerged　in　terms　of　wave　dissipation.　Further　studies　should　take　the　dynamic　growth　effect　of　oyster　reefs　into　account.