Abstract: In view of the serious damage to the sensitive components of a gamma ray detector from impacting, the influence of damping layer dimension parameters of the shock absorber on its overall natural frequency and impact resistance performance was studied. The effect of the thin-walled structure on the vibration suppression and impact transmission was also investigated. The vibration reduction was completed by proper design of the shock absorber, reasonable selection of damping layer dimension parameters, adding the secondary stage damping buffer, and improving the thin-walled structure. Finally, the design was verified through simulation and test. It is shown that the shock absorber can reduce the structural stiffness and significantly attenuate the impact. The outer diameter of the damping layer is the main factor for improving the shock resistance, as both the overall natural frequency and the impact response decrease with the increasing diameter. The thin-walled structures have an amplification effect on excitation, whose impact response can be reduced by adjusting local structures. The secondary stage damping buffer exhibits a good vibration reduction effect on the key components, and the effect is more pronounced at low frequencies. The above study may provide a reference for the shock attenuation of spacecraft with structural constraints.