The invention discloses a conducting film structure of a surface conduction field emission electron source, namely, a conducting film of an electron source is formed by a multilayer composite film which is formed by a palladium oxide film (PdO) and an amorphous carbon film, the electron transmitting performance of the conducting film can be improved by using the good electron emission stability of the palladium oxide film and the lower effective work function, the large carrier mobility, the high breakdown voltage, the wide forbidden bandwidth and the high heat conduction coefficient of the amorphous carbon film, and consequently, the emission current density and the electron emissivity of the field emission electron source are increased.