In　order　to　improve　the　corrosion　resistance　and　wear　resistance　of　Inconel　690　alloy　tube　surface,　the　laser-fused　assisted　nitriding　treatment　to　alloy　tube　surface　is　investigated.　The　microstructure,　phase　composition,　microhardness　and　corrosion　resistance　of　samples　after　treatment　are　tested　and　analyzed.　The　results　show　that　the　laser　nitriding　layer　is　mainly　composed　of　CrN　and　γ　phases　which　has　good　metallurgical　quality　without　defects　such　as　cracks　and　pores　and　the　microstructures　uniformly　distribute　with　fine　grains.　The　laser-fused　assisted　nitriding　layers　have　the　highest　microhardness　of　253　HV.　After　the　laser-fused　assisted　nitriding　treatment,　the　alloy　tube　has　better　corrosion　resistance　to　Cl-　ions　with　slight　reduction　of　corrosion　resistance　to　OH-　ions.　©　2017,　Chinese　Lasers　Press.　All　right　reserved.