A　wavelet-based　Retinex　algorithm　for　unmanned　aerial　vehicle　image　defogging　is　proposed　to　avoid　edge　fuzziness,　image　dinginess,　noise　pollution　and　inefficiency,　etc.　in　classical　Retinex.　In　light　of　different　energy　distribution　of　fog,　noise　and　edge　information　of　subjects　in　the　wavelet　domain,　this　algorithm　uses　Retinex　to　restrain　the　influence　of　the　fog,　and　adopts　the　wavelet　threshold　method　to　restrain　noise　while　preserving　the　edge　information,　in　order　to　reduce　the　influence　of　fog　and　noise　of　image.　Experiment　results　show　that　this　algorithm　can　effectively　improve　the　degradation　of　foggy　and　enhance　its　definition.