The invention discloses an organic soilless vegetable culture substrate. Under the soilless condition, vegetables are difficult to plant. The organic soilless vegetable culture substrate is characterized in that cassava bark, poultry manure and peanut bran are utilized to be simultaneously fermented with fermentation bacterium liquid, and the organic soilless vegetable culture substrate is prepared. The raw materials adopted by the organic soilless vegetable culture substrate are respectively organic matter raw materials, the reasonable and scientific mixture ratio is adopted, the vegetable planting requirement is properly met, particularly, the waste and abandoned cassava bark after the cassava deep processing is used as raw materials, nitrogen and calcium obtained through conversion after the cassava fermentation are utilized, the technical problem of soilless culture is solved, and the vegetable planting can be conveniently carried out by utilizing the organic soilless vegetable culture substrate in places without planting conditions. The organic soilless vegetable culture substrate overcomes the defects of the soilless vegetable planting in the prior art, the energy saving and the environment protection are favorably realized, the pest and disease occurrence quantity of the vegetable planting is low, the pesticide consumption is reduced, and no chemical fertilizer is used, so the product quality and yield requirement of green vegetable products can be ensured.