In this study, three-dimensional vertical graphene was prepared on copper foil using radio frequency plasma enhanced chemical vapor deposition technology with methane as carbon source. By adjusting the growth parameters, seven groups of comparative experiments were carried out. The morphology, mass and layer number of vertical graphene were characterized by scanning electron microscope and Raman spectroscopy. The field emission characteristics of vertical graphene were measured by a secondary structure field emission instrument. The relationship between the field emission characteristics of vertical graphene and its morphology, mass and density was studied. The open electric field intensity of the field emission characteristic as low as 0.29V/μm was obtained. The results show that vertical graphene is a material very suitable for field emission application and has broad application prospects in vacuum electron sources in the future.