Abstract: Considering frictions between a workpiece and the fixture elements, a mechanical model is formulated aiming at analyzing the effect of multiple clamping forces and their application sequences on contact forces. According to the principle of the minimum complementary energy, a finite element method is presented to reveal the influence of multiple clamping forces and contact forces on workpiece deformations. Furthermore, a mathematical model is proposed to optimally select the magnitude, action point and applying sequence of multiple clamping forces. Finally, a representative example is illustrated. A detailed discussion is made about how the analysis and optimal design of clamping sequences are carried out. Numerical simulation results show that the proposed method, in addition to the verification of the magnitude and action point of multiple clamping forces, can be used to study the feasibility of clamping sequences.