Patterned porous silicon (PS) films were synthesised by using hydrogen ion implantation technique and typical electrochemical anodic etching method. The surface morphology and characteristics of the PS films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). The efficient electron field emission with low turn-on field of about 3.5 V/μm was obtained at current density of 0.1 μA/cm2. The electron field emission current density from the patterned PS films reached 1 mA/cm2 under an applied field of about 12.5 V/μm. The experimental results show that the patterned PS films are of certain practical significance and are valuable for flat panel displays.