On the basis of the biological characteristics of human hands, a novel exoskeleton mechanical hand is presented for the rehabilitation of injured fingers. The exoskeleton hand developed by a modular design technology can be regulated for hands with different sizes and for driving fingers to do flexion and abduction/adduction motions independently,and it also can feedback the information of finger joints in real-time during the rehabilitation. The device keeps a rehabilitation force perpendicular to the finger bone under therapy and avoids the soft tissue damage surrounding the finger bone. The one DOF and two DOF structures of the driving mechanism are analyzed and then a kinematical model for the hand exoskeleton is established. Kinematics and dynamics of the hand exoskeleton are analyzed, and their equations are built. Furthermore, a controller architecture using an ARM processor as the kernel is presented based on SPI bus. Finally,the kinematics and dynamics simulations of the hand exoskeleton and the flexion rehabilitation experiment of the index finger are undertaken. The results indicate that the rehabilitation principle and method are correct and the repeatability is less than 5%, which demonstrates that the exoskeleton system can satisfy the rehabilitation requirements of the injured fingers.