Machining is considered as one of the most important procedures as for complicated components of polymer bonded explosives(PBX).A definitive modified time hardening theoretical creep model was used to predict clamping deformations of different structural PBX parts under various clamping forces,which affects cutting accuracy directly.Simulation of vacuum absorbed spherical shell shows that displacements of points on profile increase with latitude,and its vector has an included angle to radial.When cam-ring chuck gripping a PBX parts,both the maximum deformation and stress appear in the contact area,and the value of internal is smaller than that of the external to a certain extent.Comparing simulation of vacuum absorbed hollow hemisphere with experimental data gauged by micrometer,the creep model has a better accuracy and reliability in the first twenty minutes,and the simulational results larger than test later with a less than 10% extent error within an hour.