The present invention relates to a kind of production coco bran plant growth substrates. More specifically, a kind of production coco bran plant growth substrate shows method and simplifies method, including acidification coco bran, by the way that coco bran aqueous solution is added, it include: nitric acid, phosphoric acid and sulfuric acid, wherein 1 to 100 mole of H+ is added to every cubic metre of coco bran, thus the pH of coco bran plant growth substrate is less than 5.