The invention discloses a root strengthening anti-lodging bio-organic fertilizer. The root strengthening anti-lodging bio-organic fertilizer is prepared from the following raw materials: plant ash, swilling, peel, herbivore feces, bran, waste vegetables, cottonseed meal, crop straw, earthworm, bone meal, tea dregs, litter, microbial agents, potassium dihydrogen phosphate, starter culture, residualtea, washing water of rice. The invention also discloses a preparation method of the root strengthening anti-lodging bio-organic fertilizer. The bio-organic fertilizer can provide rich potassium fertilizer for crops, promote the transportation of protein synthesis, photosynthesis and photosynthetic products of crops, enhance the stress resistance of plants, stabilize the roots of crops, enhance the disease resistance, cold resistance, drought resistance and lodging resistance and salt resistance of the crops, improve yield, and also improve crop product quality.