Abstract: According to the characteristic and service conditions of the core-drilling device and the requirement of space environment, the deformation and stress distribution of the device were computed at low and high temperatures in store stage with the finite element analysis method based on the simplified model, then deformation and stress distribution of the device under different drilling conditions were also computed, and the temperature and displacement of key points were obtained. Finally, the temperature of sealer and the tolerance between the core pipe and soft bag were also simulated and the tolerance. And the results show that the material of each component and the designed fit clearance can meet the engineering requirements. It can provide theoretical basis for future engineering application.