The work aims to master the influence rules of counterpart surface roughness on the performance of isolation block in slewing bearing. Under the lubrication conditions of No.2 lithium grease and 20# oil, the influence of the surface roughness of bearing GCr15 rolling element on the performance of isolation blocks like PA1010 and HPb59-1 isolators was investigated by M-2000 tester. The influence rules of different loads, speed and surface roughness of counterparts on friction coefficient and wear amount were analyzed. The micromorphology of worn surface was observed and the damage mechanism of PA1010 and HPb59-1 was discussed. With the increase of surface roughness of GCr15 steel ring, the friction coefficient and wear amount increased. The influence of the tribology properties of PA1010 subject to surface roughness of counterpart was greater than that of HPb59-1. Under the condition of same surface roughness, the friction coefficient decreased slightly without much change and the wear amount increased rapidly with the increase of test load. The average wear ratio under 200, 400 and 600 N loads was 1∶1.64∶2.44 for PA1010 and 1∶2.92∶3.74 for HPb59-1. The friction coefficient of 20# lubrication oil was lower than that of No.2 lithium grease, which decreased by about 52.7% for PA1010 and 41.8% for HPb59-1 on average. The increase of counterpart surface roughness for GCr15 causes the raise of friction coefficient and wear amount, and has a greater impact on PA1010. The influence of lubricant on wear amount is closely related to the surface roughness of GCr15 steel ring. The small surface roughness has little effect. With the increase of surface roughness, the influence of lubricant becomes more obvious. All the worn surfaces of PA1010 and HPb59-1 show typical abrasive wear characteristics. The results provide experimental and theoretical reference for the mechanical design of slewing bearing.