The invention discloses a selenium-enriched strawberry organic fertilizer and a preparation method of the selenium-enriched strawberry organic fertilizer. Pine tree saw dust, a selenium-enriched ricehull powder, and a pig manure and urine mixture are biologically fermented, a processing waste of a marine product, a selenium-enriched edible mushroom dreg powder and a plant waste mixed powder are organically fermented, the mixture are finally mixed, thoroughly decomposed and fermented, the organic material is constantly decomposed and transformed and releases the energy in the form of high temperature, the fertilizer nutrient turns into effective state and quick acting state from ineffective state and sustained release state, the humification is promoted, the foul smell in the ingredient israpidly eliminated, the beneficial microorganism in the fertilizer is increased, and the fertilizer nutrient is strengthened. The selenium element in the organic fertilizer is constantly implanted inthe growth process of the strawberry, the selenium-enriched strawberry organic fertilizer is safe, environmentally friendly and efficient, is rich in physiologically active substances, nitrogen, phosphorus, potassium and microelements required for the strawberry, can resist the diseases and reduces the dose, the fertilizer efficiency lasts long, the utilization ratio of the fertilizer is high, the selenium content of the strawberry planted by using the organic fertilizer instead of the chemical fertilizer is up to 0.035 mg/kg, the shelf life of the strawberry is prolonged by 5-10 days, the cost is reduced, and the economic benefit is increased.