The present invention relates to a high thermostable and high efficient solar energy absorbing film and a manufacturing method thereof. The manufacturing method comprises the following steps. Step A: using a metal to be a base material; step B: spray welding a tungsten carbide layer on the base material; step C: executing a laser carving operation on the tungsten carbide layer to form multiple concave micro-structures on the tungsten carbide layer; step D: coating a diamond-like carbon film or a alumina film on the tungsten carbide layer and the micro-structures thereof. The solar energy absorbing film comprises a base material, a tungsten carbide layer, multiple micro-structures and a coating layer. The tungsten carbide layer is spray welded on the base material. The multiple micro-structures are formed on the tungsten carbide layer by laser carving. The coating layer is coated on the tungsten carbide layer and the micro-structures, and is a diamond-like carbon film or an alumina film. Therefore, the solar energy absorbing film of the present invention has the advantages of high thermostability, high absorbing efficiency and low emissivity.