The invention discloses a hydrotalcite-like compound/eggshell membrane composite film and a preparation method thereof and belongs to the technical field of preparation of composite-function film materials, and the composite film is researched as a chromyl adsorbent. The invention has the technical scheme that the eggshell membrane is used as a substrate and a template, and the hydrotalcite-like compound is fixed to the surface of the eggshell membrane by using an in-situ growth method, thereby obtaining an inorganic-biological composite film with a reticular structure. The invention uses the biological substrate eggshell membrane as the substrate and template for the first time, adopts an in-situ crystallization method to prepare the hydrotalcite-like compound/eggshell membrane inorganic-biological composite film, and makes a preliminary research into the applications of hydrotalcite-like materials in the field of biology. The composite film has favorable adsorbability as a chromyl adsorbent, and especially can carry out adsorption under the acidic conditions of a lower pH value, thereby saving the cost and meeting the requirements of the environment.