Abstract: Wear resistance of sulphonitrocarburized martensite stainless steel 11Cr17 was tested on MM-200 wear tester. Wear area was measured and wear morphology was observed by microscopy with three dimensional ultra depth of field. The mechanism of increasing wear resistance of sulphonitrocarburized 11Cr17 steel was analyzed by microstructure, hardness gradient, EDS spectrum and XRD pattern. The results show that the 11Cr17 steel after sulphonitrocarburizing had more excellent wear resistance than high speed steel M2 under dry friction condition, because the former had a compound layer with high hardness and solid-lubricated FeS. The wear resistance of 11Cr17 steel after sulphonitrocarburizing and high speed steel M2 under oil lubrication conditions was not differen obviously.The anti-seizure property of sulphonitrocarburized 11Cr17 steel was also excellent, which could effectively delay the time of bad wear.