Based on HSR-2M highspeed reciprocating friction and wear tester,the effects of sliding speed,load and other parameters on the tribological behaviours of 45 steel and GCr15 steel friction pair was studied in the permanent magnet magnetic field working environment,and the results were contrastively analyzed with those without magnetic field.The wear mechanism was discussed by analyzing the wear scar morphology.The results show that the magnetic field can reduce the friction coefficient and wear rate to some extent,indicating that magnetic field can improve the friction and wear properties of 45 steel and GCr15 steel friction pair.With the sliding velocity increasing,the friction coefficient and wear rate are reduced.With the load increasing,the friction coefficient is reduced,but the wear rate is increased.Without magnetic field,the wear is typical abrasive wear,worn surface is obvious furrows,and the wear system shows greater wear rate and friction coefficient.When a magnetic field is applied,it mainly is adhesive wear,and the friction coefficient and the wear rate is smaller.