The invention discloses an organic
selenium fertilizer for
selenium-rich rice paddy and a preparation method of the organic
selenium fertilizer. The preparation method comprises the following steps: (S1)
degreasing and crushing selenium-rich rice
bran, adding
sodium dihydrogen
phosphate for soaking, heating to 20-35 DEG C, and vibrating at a rotation speed, so as to obtain a material 1; (S2) adding selenium-rich
yeast into the material 1 obtained in the step (S1), heating to 28-32 DEG C, stirring, mixing, cooling, adding humate and
linoleic acid so as to obtain a material 2, adding a
granulation agent into the material 2, crushing, sending the material 2 into a granulator, and granulating, so as to obtain particles 1; and (S3) uniformly mixing a
nitrogen fertilizer, a
potassium fertilizer, a
phosphorus fertilizer, a
urease inhibitor and an
ammonia stabilizer so as to obtain a material 3, adding the
granulation agent into the material 3, and granulating,
polishing and sieving the material 3 together with the particles 1 obtained in the step (2), so as to obtain the organic selenium fertilizer for the selenium-rich rice paddy. The selenium-rich rice
bran is taken as the
raw material and is added with humate to introduce a selenium element into the fertilizer again so as to form a multi-layer granule structure, and the selenium element is slowly released, so that the selenium content in selenium-rich rice is increased, and the yield is increased.