Abstract: In order to attain the goal of saving fertilizer, cutting down production cost and protecting environment, the liquid fertilizer applicator was designed and tested in field trial based on its advantages of non-dust, non-smog, reducing environment pollution during the process of production, usage and transportation. The design of liquid fertilizer applicator was reasonable with multi-purpose usage, and it had characteristics of compact structure and convenient adjustment. The optimized working parameters by means of field trial were as follows: fertilization depth of 100～120 mm, operation velocity of 0.7 m/s and pump working pressure of 0.2 MPa. The liquid fertilizer applicator can spray drug liquid uniformly with better coverage and less mechanical damage to crops. All of detected and measured indexes reach or even exceed the design standards of this machine, which meet agronomic requirements of fertilizing crops.