NOVELTY - Microbial inoculum for degrading plant straw comprises mixture of I and II microbial agents; where microbial agent I comprises Phanerochaete chrysosporium, Bacillus and/or Streptomyces in any proportion; and the microbial agent II comprises Trichoderma, Penicillium, Aspergillus niger and/or Actinomycetes in any proportion. The Microbial inoculum comprises 50-70% of microbial agent I and the balance of microbial agent II.    USE - The microbial inoculum is useful for degrading plant straw to produce ethanol-producing product.    ADVANTAGE - The method utilizes ammonia water for treating straw to remove lignin, increases contact area of cellulose and hemicellulose, has synergistic fermentation of all microbes by providing complementary enzyme to degrade straw completely, improves resource utilization rate, is simple and easy to implement and does not cause pollution.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) preparing the microbial inoculum for degrading plant straw comprising: inoculating each single strain in a culture medium, where the culture medium comprises: peptone (10 g), yeast powder (5 g), sodium chloride (5 g) and distilled water (1000 ml), adjusting the pH to 7.4, shaking at 40 degrees C and stirring at 170 rotations per minute for 36-7 pools, diluting the microbial broth (2 billion strain /ml of broth), and mixing the microbial agent I and microbial agent II; and    (2) use of microbial inoculum for degrading plant straw to produce ethanol producing product comprising: (i) crushing the straw to obtain fine straws having particle size of 0.5-0.8 cm, (ii) soaking the fine straws in ammonia solution (0.1-1%) for 24-48 hours, purifying, removing and extruding until anhydrous outflow, (iii) adding nutrient solution into the straw after purification to prepare fermented substrate, and (iv) injecting straw degrading microbial inoculum into the fermentation substrate and fermenting for 2 days to obtain fermentation product, filtering and washing to neutrality to obtain ethanol-producing product.