The work aims to design a point field emission device with common pencil lead and carbon nanotubes, so as to enhance field emission performance through filling graphene. ITO glass was used as anode and pencil lead and carbon nanotubes formed the emission terminal. Tin base was used to fix the pencil lead and conducting resin and ITO glass were adhered to form the cathode. By comparing the field emission performance of pure carbon nanotubes and carbon nanotubes with different concentrations of graphene, the best concentration of graphene was found. SEM image was adopted to explain the reason why graphene enhanced field emission performance. All-carbon materials point field emission device was prepared and field emission performance was optimized. The point-type emitter with 7% graphene showed an excellent field emission performance with a low turn-on electric field of 1.05 V/μm, field enhancement factor of 13509 and maximum emission current of 0.75 mA. Point-type field emission device has better focusing, lower on-field strength and higher field emission current density, and has higher application value in the manufacture of X-ray sources and microwave devices.