Carbon fibers (CNFs) were surfacial metallized by electroless deposited with copper, and their field emission properties were investigated by diode test. The results indicated that the field emission properties of CNFs were affected by the thicknesses of copper. After CNFs were surfacial metallized, the volume resistivity of CNFs was decreased and field emission property was increased, respectively; increase the thin-film thickness, there appeared an optimal film thickness value for properties of field electron emission. It was found that CNFs owned the best field emission properties after electroless depositing for 15 min, with copper metal thickness as 2.1 µm and the volume resistivity down to 2.3510-4 Ω•cm. The field emission tests showed when applied voltage was 562 V, CNFs appeared bright dots, and the high luminance achieved 1388 cd/m2 under applied voltage 1013 V. Further more theoretical analyses, copper coating on CNFs surface is attributed to good electric conductivity, the low work function and the lower attenuation of electron scattering in thin-film.