The purpose of this research is to present a new method to achieve precise position tracking control for robot finger with variable stiffness mechanism. First, the variable stiffness design of the finger which is actuated by SMA-3 fibers is presented. Then, the relationship between the variation of pulling force ΔF of the bending robot finger and input voltage of SMA-3 is established. In addition, the relationship between the pulling force F and the input voltage of SMA-2 wire is established as well. Therefore, a control method based on these models for the position tracking of robot finger with variable stiffness characteristics is proposed. The experimental results show that the proposed method has better performance than traditional PID control when the stiffness changed by heating current, resulting in a reduction of maximum error by 86%.