The friction and wear tests of Copper-based powder metallurgy/Q235-B friction pair were carried out by using a multifunctional pin disk friction and wear tester.The effects of contact pressure (0.4 MPa,0.7 MPa,1.0 MPa and 1.3 MPa) on the wear surface morphology of Copper-based powder metallurgy brake pads were studied under current carrying and no current carrying conditions.The results show that under no-current carrying condition,with the increase of contact pressure,the friction coefficient and wear rate increase slowly,the surface damage and roughness of the sample increase,and the main damage mechanisms are abrasive wear and delamination.Under the current carrying condition,the friction coefficient and wear rate are the largest,the damage is the most serious and the roughness is the highest at 0.4 MPa.When the contact pressure increases to 0.7 MPa,the change trend of surface morphology damage is consistent with that under no current carrying condition.In addition to abrasive wear and delamination,there is also arc ablation.The surface roughness under current carrying condition is generally higher than that under no current carrying condition,and the surface damage is more serious.