NOVELTY - Preparing organic fertilizer comprises grinding straw, uniformly mixing fish tank silt and plant ash with grinded straw, stacking the mixture in a gap between a bottom plate and a clapboard, maintaining height of deposit, closing the gap using a heat insulating door plate, fermenting the stack with water, continuously fermenting for 2 days, atomizing 2 pts. wt. glucose aqueous solution using an atomizing device in a layered fermentation device, fermenting for 3 days, opening an air hole for 15 minutes after fermentation, then closing the air hole, and then fermenting.    USE - The method is useful for preparing organic fertilizer (claimed).    ADVANTAGE - The method is capable of rapidly preparing organic fertilizer with good smell and rich nutrition.    DETAILED DESCRIPTION - Preparing organic fertilizer comprises grinding 100 pts. wt. of straw having height of smaller than 1 cm, uniformly mixing 30 pts. wt. fish tank silt and 3 pts. wt. plant ash with grinded straw, stacking the mixture in a gap between a bottom plate and a clapboard, maintaining height of deposit to less than 15 cm, closing the gap using a heat insulating door plate, fermenting the stack with water flow from an inlet to an outlet at temperature of 70 degrees C for 12 hours to drain water, continuously fermenting for 2 days, atomizing 2 pts. wt. glucose aqueous solution having concentration of 5% using a atomizing device in a layered fermentation device, fermenting for 3 days, opening an air hole for 15 minutes after fermentation, then closing the air hole, fermenting for 4 days, 5 days or 6 days, and continuously fermenting for 1 day. The layered fermentation device comprises a wall plate whose two middle parts are parallelly connected to a bottom of a baffle plate. The wall plate, a bottom plate, a top plate and the clapboard are hollow in shape. The bottom plate is arranged far away from one side of the wall plate that is provided with the water inlet and the water outlet. Height of the water outlet is higher than the height of wall plate. The water inlet and the water outlet are provided with the heat insulation plate whose upper part is provided with the atomizing device, and lower part provided with a closed air hole arranged far away from one side of the wall plate of the top plate.