When a manipulator to grasp fragile workpieces, the contact impact force between the finger of manipulator and fragile workpieces has an important influence on the grasping stability. In this paper, based on introducing the structure model of the manipulator to grasp fragile workpieces, we present a structural form and parameter optimization of manipulator based on improving contact impact force. In order to find the appropriate operation parameters of manipulator’s finger, the finite element model is constructed for the finger of the manipulator by integrating HyperMesh and LS-PrePost to model. After the corresponding loads, constraints and contact types are applied to the finite element model, the stress and strain cloud images for the finger and the fragile parts on the contact collision process are calculated. By analyzing the calculated results, we can obtain the optimized structural parameters of the manipulator.