For the rehabilitation device, the safety of the patient who interacts directly with the robot is the most important issues. Any risks might happen must be detected as soon as possible together with their troubleshooting. This paper addresses the safety issues of the high compliant gait training robotic orthosis named AIRGAIT which actuated by additional bi-articular muscles. Firstly, common problems of the system are carefully investigated and classified into three groups based on their sources including sensor faults, actuator malfunctions, and interrupt of power sources. Secondly, the developed control system capable of detecting the failure and choosing the suitable methods for accident risk reduction. In addition, the existent of the bi-articular muscle is able to provide more safety to human during a collision. The effectiveness of the proposed method is confirmed by experimental results without the participation of any subject.