The invention discloses an intelligent automatic fertilizer applicator which comprises a base, wherein a chemical fertilizer storage box, a square box, a control box, a small bulge and a solar panel are arranged on the base; a steering mechanism is arranged on the lower surface of the base; a chemical fertilizer storage and usage mechanism is arranged inside the chemical fertilizer storage box; asoil constituent detection mechanism, an automatic driving device and a remote control device are arranged inside the square box; the steering mechanism comprises a support frame, a groove, an L-shaped supporting rod I, an L-shaped supporting rod II, a beam, a gear shaft, a bearing I, a stepping motor and a gear; a monitoring mechanism is arranged on the square box; the chemical fertilizer storageand usage mechanism comprises a chemical fertilizer placement box, a baffle, a chemical fertilizer storage box, a through hole I, a circular iron cover, a spring, an electromagnet, a plank, a throughhole II, an iron pipe I and an iron pipe II; and the soil constituent detection mechanism comprises a control box, a controller, a detection box, a soil constituent analyzer, a U-shaped pipe, a fan and an infrared sensor I. The intelligent automatic fertilizer applicator disclosed by the invention has the beneficial effects of simple structure and high practicality.