A planar Schottky barrier diode comprises an N-type heavily-doped silicon substrate, an N-type light-doped epitaxial layer, a P-type heavily-doped loop region, a thin oxide layer, a field oxide layer, a Schottky barrier layer and multiple layers of metal and is characterized in that a P-type light-doped loop region is arranged in the N-type light-doped epitaxial layer outside the P-type heavily-doped loop region, the thin oxide layer is arranged on the P-type heavily-doped loop region and the P-type light-doped loop region, the field oxide layer is arranged on a part of the P-type light-doped loop region and on a part of the N-type light-doped epitaxial layer outside the P-type light-doped loop region, and the Schottky barrier layer is formed on a part of the P-type heavily-doped loop region and on a part of the N-type light-doped epitaxial layer. With the diode disclosed by the invention, the pressure resistant efficiency of the P-type heavily-doped loop region can be effectively improved, the surface field of a Schottkey barrier region can be further enhanced by reducing the junction depth of the P-type heavily-doped loop region, so that the lightning resistance ability of the planar Schottkey barrier is improved, the positive conducted voltage drop can be reduced, and the positive surge capability is improved.