Bidirectional switching devices are widely employed in photovoltaic, energy, and electric vehicle applications. The superior physical properties of diamond are expected to fulfill the requirements of switching devices for low on-resistance and high breakdown voltage. In this study, for the first time, a depletion-mode bidirectional switching MOSFET device with a common-drain anti-series monolithically integrated structure was fabricated using hydrogen-terminated diamond with a (100) crystal orientation. The device utilizes a 100nm Al₂O₃ layer as both the gate dielectric and the passivation layer. The device exhibits an on/off ratio of 10⁹, a threshold voltage of 52.8 V, excellent gate control capability, and ultra low gate leakage current. By short circuiting the two gate electrodes, the device operates in a bidirectional switching mode, enabling bidirectional current flow when the applied bias voltage exceeds the threshold voltage. In the bidirectional conduction mode, the maximum output currents are 180.52 mA/mm and 170.90 mA/mm, and the corresponding on resistances are 0.20 kΩ·mm and 0.23 kΩ·mm, respectively, satisfying the demand for low on resistance in switching devices. When one of the gate electrodes is shorted to the adjacent ohmic contact electrode, voltage regulation allows current flow in only one direction while blocking current in the opposite direction. The gate drain breakdown voltages of the bidirectional switch device are measured as -358 V and 366 V when the two gate electrodes are individually shorted to their respective neighboring source electrodes, with a breakdown electric field of approximately 0.22 MV/cm. With further optimization of the device structure and improvement of the gate dielectric quality, this device shows considerable potential for high voltage applications. This work provides a new application demonstration scenario for hydrogen terminated diamond power devices.