The invention discloses a special additional fertilizer for container plants and a preparation method and application thereof. Active ingredients of the fertilizer composition comprise a fertilizer, a sourness conditioning agent, a rare earth additive and skeleton powder, wherein the fertilizer consists of a nitrogen fertilizer, a phosphatic fertilizer, a potash fertilizer and secondary and trace element fertilizers; the sourness conditioning agent is selected from at least one of sulphamic acid, urea sulfate, urea nitrate, urea hydrochloride, urea phosphate, sulphur powder and citric acid; the skeleton powder is selected from at least one of calcium-containing rocks, magnesium-containing rocks, metal aluminosilicate, carbon and phosphate ores. The fertilizer is balanced in nutrition, is complete in types of nutrient elements and not only gives consideration to both nutrient supply and counteraction for raising of pH of a growth medium, which is caused by watering of alkali tap water, but also avoids failure of nutrients in pots. The fertilizer is pressed into particles for use, gives consideration to watering, fertilization and sourness conditioning, is very easy to cater to application of people to planting of the container plants which like neutral and (or) acidic growth medium, and is simple and convenient to operate.