By simulating the physical structure of the human hand, a new type of under-actuated dexterous hand system was created. The structure of the under-actuated dexterous hand was introduced, and a new driven method based on the sequential under actuated joint mechanism was proposed. The movement spatial domain of the fingertips was drawn by using Matlab Robotics Toolbox from the kinematic of view. The results show that the joint of the sequential driving method has larger movement spatial domain. Finally, the scheme and the circuit of the control system are introduced, and the experiment realizes the primary movement of flexion/extension and adduction/abduction of under-actuated dexterous hand, and has good control effect.