This study demonstrated preparation of Mo-Cu-CNTs composites by reflux treatment of carbon nanotubes along with chemical and mechanical activation. We used carbon nanotubes as raw materials and added concentrated sulfuric and nitric acids using the concentrated acid reflux method to activate them. Moreover, we modified the carbon nanotubes by chemical activation method at 100°C. Further, the activated carbon nanotubes and copper molybdenum powder were mechanically activated into mixed powder. Finally, molybdenum-based carbon nanoencapsulation material was prepared by powder metallurgy. Several characterization techniques revealed that the concentrated acid reflux method generated functional groups on the surface, improving the pressing performance and wettability, thereby preventing the occurrence of an interfacial reaction. Furthermore, the composite material of carbon nanotube and molybdenum matrix was realized by the mechanical and chemical activation methods. Thermal conductivity experiments revealed efficient heat transfer of the composite material, and carbon nanotube density variation characteristics showed low density acid treatment after 24 h. The conductivity of the sintered body reached a maximum of 22.4 MS/m, and the thermal conductivity was found to be the highest, reaching 146 Wm− 1K− 1'. The composite material obtained by sintering at 1100°C exhibited the highest Vickers hardness with a value of 214 HV.