<p>Soft modular biomimetic robots, driven by flexible actuators, are extensively used in various fields due to their excellent flexibility, confined environmental adaptability, and isomorphism, particularly in underwater engineering. However, existing flexible modules typically possess no more than two degrees of freedom for structural limitations. This paper proposes a biomimetic robotic module that is supported by a spring and actuated by water hydraulic artificial muscles (WHAMs). The module is capable of achieving axial contraction and bidirectional deflection movements, thus providing a total of three degrees of freedom (3-DOF). To avoid the coupling problem of the three-actuator module, the module comprises two orthogonal pairs of WHAMs and independently controls both the module contraction and the deflection in two degrees of freedom through three valves. The pressure sensors and angle sensors are arranged within the three-degree-of-freedom module. The pressure sensors are used to detect the working pressure of each WHAM, whereas the angle sensors are employed to monitor the deflection status of the module. Furthermore, the experimental results demonstrate that the module possesses a certain load-bearing capacity. The continuum robot composed of this module has the potential to perform load-carrying operations in complex underwater environments.</p>