The invention discloses a multifunctional liquid organic and inorganic fertilizer and application thereof, and relates to the field of fertilizer preparation. The multifunctional liquid organic and inorganic fertilizer is prepared from the following components in parts by mass: 60 to 78 parts of liquid organic fertilizer, 20 to 40 parts of inorganic fertilizer, 0 to 2 parts of chelating agent, and 0 to 2 parts of growth regulator, wherein the inorganic fertilizer comprises a high-nitrogen inorganic fertilizer, a high-phosphor inorganic fertilizer and a high-potassium fertilizer; the components are uniformly mixed to prepare the liquid organic and inorganic fertilizer. The liquid organic and inorganic fertilizer has the characteristics that the nutrient content is high, the compounding of organic and inorganic nutrients is reasonable, the state of solution or suspension is relatively stable, the liquid organic and inorganic fertilizer can be used as a water fertilizer to apply, the different requirements of crops in different growth periods are met, and the output of crops is increased.