Cottonseed hull composite substrate for morchella esculenta and preparation method of cottonseed hull composite substrate

The preparation method comprises the following steps: crushing cottonseed hulls, wheat, corn flour, crop straws, rice husks, wheat bran and bagasse, performing sieving, performing standing and aging for 5-10 days, adjusting the water content, adding a compound microorganism fermentation bacterial liquid and sucrose, performing uniform stirring, and performing fermentation so as to obtain a decomposed base material; the preparation method comprises the following steps: adding sodium alginate into water, uniformly stirring, freezing, freeze-drying, crushing, sieving, adding into a calcium chloride solution, carrying out ultrasonic treatment, washing with water, drying, adding perlite ore sand, fly ash and anhydrous sodium metasilicate, uniformly stirring, adding water, stirring, adding hydrogen peroxide, continuously stirring, keeping the temperature at 50-60 DEG C for 10-20 hours, cooling to room temperature, drying, and crushing to obtain a porous matrix; and uniformly stirring gypsum, lime, urea, calcium sup