Preparation method of paddy seedling raising medium

The invention discloses a preparation method of a paddy seedling raising medium. In the preparation method, livestock and poultry feces is used as foodstuff for earthworm to provide an environment suitable for growth of earthworm, and the earthworm feces generated by earthworm treatment is screened into earthworm feces with the particle size of 1-4mm, and uniformly mixed with nutrient soil and vermiculite to prepare a novel organic medium, wherein the particle sizes of vermiculite and the nutrient soil are 3-5mm. The medium comprises the components by volume percent: 50-60% of earthworm feces, 30-40% of vermiculite and 10-20% of nutrient soil. The medium is simple in preparation method, rich in resources, inexpensive in materials, sufficient in nutrients and stable in property, changes wastes into valuables, and reduces environmental pollution; and used for paddy seedling raising, the medium improves the paddy plug seedling raising quality, reduces the seedling raising steps (like fertilization) and the cost, and promotes the industrialized development of paddy machine seedling transplanting.