The invention discloses a production method for an adhesive-free straw density board. The production method for the adhesive-free straw density board comprises the following steps: cutting wheat straw to be small pieces; pre-soaking in an alkaline extraction agent and placing for 1-2 h; executing separating brooming to the wheat straw by a twisting separating integrated extraction machine, sending to a pulp hanging machine after extracting to be complete fine fibers; flat-forming by a circular net, hot-press-forming by a hot press machine, and drying to form the board, finishing and shaping by an edge saw. Any adhesives are not added in the process, the straw fibers are interweaved by itself completely, and the straw contains one adhesive, the straw is adhered to form the board by the efficacy of the adhesive contained in the straw in the hot press process, and the board has the advantages of high strength, good toughness and non-formaldehyde release. The method has the characteristics of low cost, large production, and simple manufacturing process.