Taking the nose landing gear shock absorber of SR20 aircraft as an example,a 3D model of the shock absorber was established by reverse modeling method,and Fluent was used to conduct fluid simulation.The correctness of the simulation model was verified by bench test.On this basis,the influence of structural parameters on the dynamic performance of shock absorber was explored by changing the diameter of the normal hole,the width of the oil guide groove,the depth of the oil guide groove,the diameter of the piston rod and the diameter of the one-way valve.The results show that the diameter of the normal hole has less influence on the dynamic performance of the shock absorber than the other four parameters；the flow area of the oil guide groove has a great influence on the dynamic performance of the shock absorber,and the influence of the width of the oil guide groove is higher than that of the depth of the oil guide groove；with the decrease of the flow area of the oil guide groove,the median recovery damping force and the median compression damping force of the shock absorber become larger and change obviously；the diameter of the piston rod decreases and the damping force of the shock absorber increases;when the diameter of one-way valve decreases,the recovery damping force of shock absorber remains unchanged,while the median compression damping force increases.