The invention provides an acidic soil adjusting fertilizer. The acidic soil adjusting fertilizer is prepared from the following components by weight: 45 to 55 parts of plant ash, 10 to 25 parts of calcium powder, 8 to 12 parts of humic acid, 8 to 12 parts of modified plant straw, 4 to 6 parts of organic soil, 4 to 6 parts of bamboo charcoal, 2 to 4 parts of sawdust, 1 to 3 parts of olive residue, 2 to 4 parts of sea mud, 2 to 4 parts of calcium superphosphate, 1 to 3 parts of borax, 0.4 to 0.6 part of alpha-isolupanine, 1 to 3 parts of urea, 0.4 to 1 part of compound sodium nitrophenolate, 1 to 2 parts of tea residue, 1 to 2 parts of potassium fulvate, 0.4 to 1 part of shell powder, 1 to 2 parts of meerschaum powder, 1 to 2 parts of potassium chloride, 1 to 3 parts of modified corn starch, 0.4 to 1 part of pinecone, 1 to 2 parts of chelated magnesium, 1 to 2 parts of garlic extract and 1 to 2 parts of chinaberry extract. The acidic soil adjusting fertilizer can retain fertilizer and water and realize sustained release and controlled release, is slightly alkaline, has high biotic potassium content, is a superexcellent acidic soil amendment since common soil is slightly acidic and lacks potassium, eliminates a pollution source of a biomass power plant and better protects the ecological environment.