A bi-directional electromechanical valve comprising a cylindrical upper cover, two semi-cylindrical permanent magnets, two semi-cylindrical cases, a reverse U-shaped coil set, a cylindrical armature, a valve stem, a first spring and a second spring. The electromechanical valve can be opened and closed bi-directionally in a quick and powerful manner. With an integrated round-shaped design, the electromechanical valve not only reduces the dimensions, but also equalizes the valve wear caused by rotating valve during engine operations. The specially designed cylindrical armature and its button-shaped bottom provide a stronger magnetic holding force to improve the strokes of the armature. The design of a single coil set and permanent magnets reduces the coil volume and the driving power effectively. The armature will stop at a fail-to-safe position at a power failure to provide a better driving way for an engine intake/exhaust valve.