The invention discloses organic fertilizer capable of improving the survival rate of garden flowers. The organic fertilizer is prepared from the following raw materials: dry pond sludge, peanut bran, soybean meal, wine dreg, pearlite, mushroom residue, pig manure, cassava residue, urea, potassium chloride, ammonium nitrate, ammonium molybdate, potassium sulfate, borax, manganese sulfate, zinc sulfate, potassium dihydrogen phosphate, phosphoric acid powder, a modified oxygen-increasing agent, a modified slow-release agent and filling. The invention further provides a preparation method of the organic fertilizer capable of improving the survival rate of the garden flowers; the organic fertilizer provided by the invention contains rich nutrient substances needed by the growth of the flowers and can provide abundant oxygen gas to the growth of roots of the flowers, so that the survival rate of the flowers is effectively improved.