This paper investigates a control scheme for the visual servoing of a legged mobile robot equipped with a fixed monocular camera. The kinematics of the legged mobile robot and trifocal tensor-based visual servoing are employed to allow the robot to achieve the desired location. By investigating the trifocal tensor between the initial, current and desired location, the approach has no need for transcendental knowledge of the three-dimensional geometry of the observation target. The feature points are directly extracted from the images to evaluate the trifocal tensor. Furthermore, a controller is designed for visual servoing task, and a Lyapunov-based approach is used to analyze the stability of the control system. With the aid of MATLAB software, a simulation is implemented to verify the effectiveness of the proposed method.