This present work aims to improve the hardness and wear resistance of austenitic stainless steels. The plasma ni-triding treatment of the austenitic stainless steel surface was performed by arc discharge ion source coupled with axial magnetic field. The surface morphology and thickness of nitrided layer were analyzed by field emission scanning electron microscope. The wear resistance and hardness of nitrided specimens were investigated by ball-disk friction wear tester and Vickers microhardness tester. X-ray diffractometer and X-ray photoelectron spectrometer were used to analyze the phase structure and composition of nitrided layer. When the magnetic field intensity was lower than 80 Gauss, the nitriding layer was mainly composed of an expanded austenite phase (γN phase). With the increase of the magnetic field intensity, iron nitride and chromium nitride phase gradually precipitated in the nitrided layer and the thickness of the nitrided layer firstly increased and then decreased and finally increased. With the increase of the magnetic field intensity, the microhardness of the surface of the nitrided layer firstly increased and then slightly decreased when the intensity reached the maximum value of 1100HV0.05. Compared with the non-nitrided sample, the wear rate of the nitrided sample was significantly reduced and the lowest wear rate was obtained at a magnetic field intensity of 80 Gauss. After the axial magnetic field is coupled with the arc discharge ion source, the nitriding efficiency is greatly improved and the surface microhardness and wear resistance of the nitrided samples also increase.