NOVELTY - Compost dehydrating fungal inoculum comprises Penicillium oxalicum (F12 CGMCC No.3682) and a potato dextrose agar culture medium as a slant medium. The culture medium comprises e.g. potassium dihydrogen phosphate (2 g), ammonium sulfate (2.5 g), magnesium sulfate heptahydrate (0.3 g), calcium chloride dihydrate (3 g), ferrous sulfate heptahydrate (5 mg), manganese sulfate (1.6 mg), zinc sulfate heptahydrate (2 mg), cobalt chloride (1.7 mg), Tween-80 (RTM: Non-ionic surfactant) (1 ml), a complex carbon source (20 g) and distilled water (1000 ml).    USE - The inoculum is useful in plant compost and microbial inoculum producing industries.    ADVANTAGE - This microbial inoculum reduces the moisture content in livestock manure (10-20%) and hence reduces the amount of auxiliary materials; reduces the cost; and improves the quality of the organic fertilizer.    DETAILED DESCRIPTION - Compost dehydrating fungal inoculum comprises: Penicillium oxalicum (F12 CGMCC No.3682) and a potato dextrose agar (PDA) culture medium as a slant medium. The culture medium comprises potassium dihydrogen phosphate (2 g), ammonium sulfate (2.5 g), magnesium sulfate heptahydrate (0.3 g), calcium chloride dihydrate (3 g), ferrous sulfate heptahydrate (5 mg), manganese sulfate (1.6 mg), zinc sulfate heptahydrate (2 mg), cobalt chloride (1.7 mg), Tween-80 (RTM: Non-ionic surfactant) (1 ml), a complex carbon source (20 g) and distilled water (1000 ml) as a shake flask culture medium and fermentation culture medium, where the pH of the culture medium is 4-6. The complex carbon source comprises bran and microcrystalline cellulose in a weight ratio of 4:1. The slant strain, shake flask strain and the fermentation culture medium are cultured to obtain a liquid microbial inoculum or the liquid microbial inoculum uses the sterilized bran or turf as an adsorbent for preparing the liquid microbial inoculum into a solid microbial inoculum. An INDEPENDENT CLAIM is also included for preparing the microbial inoculum, comprising: (i) preparing a PDA solid medium and allowing to stand to obtain a slant culture, preparing the shake flask culture medium by providing potassium dihydrogen phosphate (2 g), ammonium sulfate (2.5 g), magnesium sulfate heptahydrate (0.3 g), calcium chloride dihydrate (3 g), ferrous sulfate heptahydrate (5 mg), manganese sulfate (1.6 mg), zinc sulfate heptahydrate (2 mg), cobalt chloride (1.7 mg), Tween-80 (RTM: Non-ionic surfactant) (1 ml), a complex carbon source (20 g) and distilled water (1000 ml), where the pH of the culture medium is 4-6, the complex carbon source is composed of bran and microcrystalline cellulose in a weight ratio of 4:1, the fermentation culture medium is identical to the shake flask culture medium, providing bran or turf as an adsorbent, sterilizing at high temperature, cooling to room temperature and allowing to stand; (ii) inoculating Penicillium oxalicum (F12 CGMCC No.3682) on the slant medium, culturing for 3-4 days in an incubator at 28-32 degrees C, removing the medium and directly placing into a refrigerator for storing; (iii) preparing the slant strain into a spore suspension, inoculating the spore suspension (4-6%) into the shake flask culture medium (50 ml), culturing for 48-96 hours in a table concentrator with a speed of 120-220 rotations per minute at 28-32 degrees C, removing and directly using the product or storing in a refrigerator; (iv) adding the fermentation culture medium into a fermentation tank, sterilizing via steam for 30 minutes at 121 degrees C, maintaining the pressure of the tank body at 0.02-0.04 MPa, cooling to 28-32 degrees C, inoculating the shake flask culture strain (3-7%) into the fermentation tank under the protection of flame, culturing under a rotating speed of the stirrer at 120-220 rotations per minute at 28-32 degrees C, where the amount of aeration is 4 m3/hour, the pressure of the tank is 0.02-0.04 MPa and the pH is 4-6, cultivating for 96-144 hours until the fresh weight of the mycelium in the fermentation liquid reaches 0.5 g/ml; and (v) adding the fermentation liquid into bottles, sealing to obtain the liquid microbial inoculum or evenly mixing the fermentation liquid via the sterilized absorbent in a weight ratio of 1:5, absorbing, packing and sealing to obtain the solid microbial inoculum when the amount of the live strain reaches above 20 million colony forming unit/g.