Abstract: The application discloses a composite reinforced moisture-proof fiberboard, and a preparation apparatus and method thereof, and belongs to the technical field of moisture-proof fiberboard preparation apparatus. A wooden board that needs an adhesive application process is placed on a conveying assembly and conveyed to a lower part of a grinding disc assembly. Then, a first levelling assembly, a second levelling assembly, and a vertical electric telescopic rod are started to adjust the grinding disc assembly to perform grinding and adhesive application on the wooden board. After adhesive application is completed, the conveying assembly is started again to drive the wooden board to move to perform high temperature drying treatment through a high temperature drying assembly. An adhesive solution thrown out during grinding and adhesive application falls onto side return covers and flows back to a recovery pool for collection and reuse.