Graphene reinforced copper-based composites were fabricated by powder metallurgy method.Effect of ballmilling speed,ballmilling time and ball-percentage of omnidirectional planetary ball mill on density,micro-hardness,conductivity and tensile properties were studied.The microscopic morphology of composites was analyzed by scanning electron microscope.The results show that graphene shows good dispersibility in copper matrix by using appropriate ball-milling parameters.Longer ball-milling time and quicker ball-milling speed generate aggregation of graphene,which results in weak bond between graphene and copper matrix.With the increase of ball material ratio,the conductivity,tensile strength and elongation of composites are improved.While the ball-milling speed is 400 r/min,the micro-hardness and conductivity of composites show similar trend.Ball milling time directly affects the dispersion effect of graphene in copper matrix,while ball milling speed and ball material ratio affect the plastic deformation of copper powder particles and the effective combination of graphene and copper matrix.In this experiment,the optimum ball-milling parameters are ball material ratio of 3∶1,ballmilling speed of 300 r/min and ball-milling time from 6 h to 8 h.