The invention discloses a slow release fertilizer used for rice planting. The fertilizer is prepared from urea, monoammonium phosphate, potassium chloride, ammonium chloride, diammonium phosphate, calcium triple superphosphate, zinc sulfate, ammonium molybdate, ammonium nitrate complex, gamma-polyglutamic acid, attapulgite, modified sepiolite powder, kaolin powder, talcum powder, stannous chloride, sodium bisulfite, boric acid, oxalic acid, cow dung, soybean meal, furfural residues, corn straw, rape-seed cakes, bagasse, fly ash, medical stone, humic acid, EM strain, hydroxymethyl cellulose and modified sustained-release preparation. The invention further provides a preparing method of the slow release fertilizer used for rice planting. The slow release fertilizer used for rice planting has excellent slow release performance, can provide rich nutrient substances, promote the growth of the rice, increase the yield of the rice, and improve the quality of the rice.