NOVELTY - Preparing active carbon earthworm cast organic fertilizer involves stacking and fermenting a mixture of animal dung and sludge (50-70 parts), microbial starter culture (0.01-1 parts), pH conditioner (3-12 parts) and straw expander (20-35 parts) to obtain a primary fermented product; stacking the product to obtain a decomposed raw material; adding active carbon (5-20 wt.%), adding pH conditioner to obtain a substrate; paving the substrate, spraying earthworms on substrate; and filtering the collected earthworm casts, drying, to form the active carbon earthworm cast organic fertilizer.    USE - For preparing active carbon earthworm cast organic fertilizer (claimed) useful for fruit, vegetable, food, flower and wood, and tea.    ADVANTAGE - The method provides enhances 20.3-30.5% of fertilizer yield.    DETAILED DESCRIPTION - Preparing active carbon earthworm cast organic fertilizer involves uniformly mixing animal dung and/or sludge (50-70 parts) and microbial starter culture (0.01-1 parts); adding pH conditioner (3-12 parts) and straw expander (20-35 parts) into the mixture, adjusting the water content of the mixture at 55-65% adjusting the pH value of 5-8, and adjusting the C/N value of 20-30 to form a mixture; stacking and fermenting the mixture for the first time, providing oxygen in the fermenting device through overturning and ventilating, overturning the stack when the temperature of the mixture is higher than 60 degrees C, primary stacking and fermenting for 25-35 days to obtain a primary fermented product; stacking the primary fermented product into the thickness of 30-40 cm, carrying out a secondary fermenting process, stacking and fermenting the primary fermented product till completely decomposed to obtain a decomposed raw material; adding active carbon (5-20 wt.%), adding the pH conditioner, adjusting pH value of 6-9 to obtain a substrate; paving the substrate with the thickness of 10-20 cm, spraying earthworms on the substrate, where the amount of the earthworms is 50-150 kg/each Mu substrate, covering straws, spraying water, collecting earthworm cast for each 1-2 week, and adding the substrate at the same time; and filtering the collected earthworm casts, removing impurity, pelleting by a pelleting apparatus, shaping, discharging, drying, cooking, removing dust, detecting, packaging to form the active carbon earthworm cast organic fertilizer.