Recent years the study on rehabilitation robotics has become the interdisciplinary research hot spot in medical rehabilitation engineering and robotics fields. In this paper, to improve the interaction capability of rehabilitation training robot, the virtual reality technology and robotics technology are combined together, and the lower limb rehabilitation training robot system based on virtual scenario interaction is studied. The Kinect sensor was used to acquire the human skeleton information, Unity3D game engine and 3D Studio Max software were used to develop the virtual environment for scenario interaction. The gait synchronization control algorithm for the patient and virtual character was designed, and the synchronous interaction in the rehabilitation training process was realized. The experiment results indicate that the gait synchronization control algorithm is effective, humancomputer interaction is friendly. The proposed gait synchronization control algorithm could help and motivate the stroke patients realize active rehabilitation training.