NOVELTY - Method for preparing selenium-enriched bio-organic fertilizer, involves (a) mixing and crushing mixture of corncob and corn kernel with microbial agent, and crushing oyster and bean straw, (b) mixing pig manure and selenium-enriched bentonite to obtain mixture (B), mixing and crushing grass seeds and wheat to obtain powder (B), mixing products obtained in step (a) with e.g. mixture (B), powder (B), and calamine powder, adding water and fermenting mixture, (c) adding enzyme and fermenting the mixture, and (d) adding sodium selenite and processing obtained product.    USE - The method is useful for preparing selenium-enriched bio-organic fertilizer (claimed).    ADVANTAGE - The method is simple to perform, and prepares fertilizer containing high content of organic selenium. The fertilizer improves selenium content of soil, and thus improves absorption rate of selenium by crops.    DETAILED DESCRIPTION - Method for preparing selenium-enriched bio-organic fertilizer, involves (a) mixing mixture of corncob and corn kernel with microbial agent in a mass ratio of 50:1 to obtain mixture (A), crushing obtained mixture to obtain powder (A), and then crushing oyster and bean straw to 100-120 mesh size, respectively, (b) mixing pig manure and selenium-enriched bentonite to obtain mixture (B), mixing and crushing grass seeds and wheat in a mass ratio of 4:1 to obtain powder (B), mixing the powder (A), powder (B), mixture (B), nitrogen, potassium and phosphorus (NPK) fertilizer, mixture comprising humus and crab shell powder in a mass ratio of 1:6, calamine powder, oyster powder and bean straw powder, adding water for immersing the mixture, covering the mixture using plastic film, and fermenting the mixture for 25-30 days, where pig manure and selenium-enriched bentonite is in a mass ratio of 4:1, (c) adding 500 times of 1-3 parts enzyme to fermented product, sealing obtained mixture, and fermenting the mixture for 10-12 days, and (d) adding 3-5 parts sodium selenite as selenium additive, uniformly stirring obtained mixture, drying the mixture for 3 days until water content of the mixture reaches 45-55%, adding microelement to the mixture, uniformly stirring the mixture, feeding the mixture to an extruder, extruding the mixture, and then granulating and drying obtained product.