The　surface　of　AZ91　alloy　for　automobile　engine　was　modified　by　plasma　spraying　and　laser　cladding　treatment,　the　microstructure　and　corrosion　resistance　of　laser　cladding　Al-Si　layer　were　studied　by　means　of　metallographic,　scanning　electron　microscope,　XRD,　hardness　and　polarization　curve　test.　The　results　show　that　the　laser　cladding　layer　is　mainly　composed　of　α-Al　and　(α-Al+β-Si)　eutectic　structure;　the　microhardness　of　laser　cladding　layer　is　higher　than　that　of　plasma　spraying　coating,　and　the　microhardness　of　the　two　kinds　of　coatings　are　higher　than　that　of　matrix　alloy;　the　corrosion　resistance　from　high　to　low　order　is　laser　cladding　coating,plasma　spraying　coating　and　AZ91　alloy.　©　2016,　Chinese　Mechanical　Engineering　Society　of　Heat　Treatment.　All　right　reserved.