Al was used for diffusion bonding with FeNiCoCrMn high-entropy alloy （HEA） and its six subsets （Ni、NiCo、FeNi、FeNiCo、NiCoCr、FeNiCoCr） by Spark Plasma Sintering （SPS）. The influences of chemical composition on the microstructure， element distribution and phase composition of the interfaces after bonding were investigated in detail， as well as the final microhardness. The results reveal that FeNiCoCrMn HEA had a better diffusion barrier effect on Al than its subsets， and the minimum thickness of the IMC diffusion layer after bonding with Al is only 14.5 μm. The intermetallic compounds （IMCs） generated at the interfaces of Ni， NiCo and FeNi after bonding were mainly Al3Ni-type IMC， while the interfaces of FeNiCo， NiCoCr， FeNiCoCr and FeNiCoCrMn after bonding were mainly Al13Fe4-type IMC， and the greater the proportion of Al13Fe4-type IMC in their respective IMC diffusion layers， the more significant the softening effect of the interface. The interface softening effect of the FeNiCo alloy and Al after bonding was the most obvious， and the lowest interface hardness value was only of 424 HV.