As　to　the　problem　of　sound　event　detection　in　low　Signal-Noise-Ratio　(SNR)　noise　environments,　a　method　is　proposed　based　on　discrete　cosine　transform　coefficients　extracted　from　multi-band　power　distribution　image.　First,　by　using　gammatone　spectrogram　analysis,　sound　signal　is　transformed　into　multi-band　power　distribution　image.　Next,　8×8　size　blocking　and　discrete　cosine　transform　are　applied　to　analyze　the　multi-band　power　distribution　image.　Based　on　the　main　Zigzag　coefficients　which　are　scanned　from　the　discrete　cosine　transform　coefficients,　features　of　sound　event　are　constructed.　Finally,　features　are　modeled　and　detected　through　random　forests　classifier.　The　results　show　that　the　proposed　method　achieves　a　better　detection　performance　in　low　SNR　comparing　to　other　methods.　©　2018,　Science　Press.　All　right　reserved.