Holefertilizing technology can be used for fixedpoint, quantitative and accurate fertilization while seeding is in operation, which is an effective method to improve the fertilizer use efficiency of corn, soybean and other crops. During the fertilizer transfer process of the holefertilizing apparatus, the rigid contact of fertilizer plate with fertilizer protection cavity caused the phenomenon of fertilizer blocking, which seriously affected the stability of fertilizer delivery. Thus a flexible fertilizer protection method was put forward and a flexible fertilizer protection mechanism was designed by using the nylon fiber which was in the shape of plum flowers. The theoretical calculation and finite element analysis of the mechanical property of single nylon fiber was carried out, the effect of the structural parameters of nylon fiber on the stress was obtained and the diameter of the selected fiber was determined as 0.1mm. The analysis of fiber bundle structure showed that the fiber length should be 13mm and the mounting hole diameter should be 4mm, to ensure the safe distance of mounting hole and reasonable clearance of brush bundle. EDEM software was used to simulate the stress changes of each wall during the process of fertilizer group compressed in fertilizer cavity, the negative clearance between fertilizer plate and bottom fertilizer protection brush was designed as 1.6mm and 0.5mm with side fertilizer protection brush. Flexible fertilizer protection mechanism was designed and the test results showed that there was no fertilizer blocking problem, the rotary torque of the fertilizer plate was 4.71N·m which was reduced by 58.54% compared with the original mechanism without flexible fertilizer protection mechanism. This mechanism could effectively avoid the fertilizer blocking problem, reduce the resistance of fertilizer delivery and insure the stability of the fertilizer delivery. The research result might provide a new approach for precise fertilizer delivery.